Analysis of the Relationship between QoS and SNR for an 802.11g WLAN

Resumo-Este trabalho apresenta um completo estudo sobre a variação da qualidade de uma comunicação de voz em uma rede WLAN devidoàs diversas degradações na interface aérea, avaliando como um determinado modelo de desvanecimento (Fading) afeta a qualidade de uma comunicação VoIP.Na realização dos testes foi empregada uma rede WLAN (IEEE 802.11g) real totalmente controlada e isolada, onde um emulador de canal de radiofreqüência (RF) que tem programado diferentes modelos de desvanecimento (fading),é conectado entre dois terminais VoIP que percorrem uma comunicação de voz. A qualidade da comunicação de voz, queé avaliada objetivamente, varia para cada modelo de fading empregado. Durante a realização dos testes foram medidos simultaneamente os parâmetros da rede IP e parâmetros RF. Na avaliação de qualidade da comunicação de vozé utilizada a ferramenta ITU-T P.862.1, a qual atribui umíndice MOS a cada um dos testes realizados. Também são testados os codificadores de Voz G.711 e G.729, podendo-se avaliar o desempenho de cada um deles nos diferentes cenários implementados. Os resultados demonstram como os diferentes modelos de fading afetam a qualidade da comunicação e a relação existente com os parâmetros da rede IP, em especial o jitter.Palavras-Chave-WLAN, VoIP, MOS, modelo de canal, desvanecimento, codificador.

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“…Segundo [22], uma faixaótima de SNRé de 34 a 90 dB para aplicações em tempo real como comunicações VoIP e videoconferência.…”

Section: Resultsunclassified

Avaliação da Qualidade de uma Comunicação VoIP em uma rede WLAN real com diferentes Modelos de Desvanecimento

Pivaro¹,

Rodríguez²,

Alfaia³

et al. 2011

Anais De XXIX Simpósio Brasileiro De Telecomunicações

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Section: B Queuing Theorem For Wmnmentioning

confidence: 99%

“…The measurements in [9] provide the information of probability of successful transmission as a function of Signal to Noise Ratio (SNR). Therefore, this paper adopts the relation of p(x) and SNR presented in [9] for taking the physical environments into account. After concerning p(x), the throughput T(x) is calculated by where H is the total number of hops, P b (x) denotes the blocking probability of M/M/1/K model, P 0 (x) denotes the probability of having empty queue in M/M/1/K model, q(x) is the forwarding probability of packet.…”

Section: B Queuing Theorem For Wmnmentioning

confidence: 99%

Design of gateway locations in an indoor WMN

Sauram

Uthansakul

2009

2009 6th International Conference on Electrical Engineering/Electronics, Computer, Telecommunications and Information Technolog

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In literatures, the performance of Wireless Mesh Network (WMN) has been investigated through end to end delay and throughput by assuming the same quality on each hop. However, this assumption is hardly true in practice due to the physical obstructions in wireless link. In this paper, the design of gateway locations in an indoor scenario has been presented by taking a physical environment into account. The simulation results show that throughput and delay are significantly influenced by changing the location of gateway. This paper does not only provide a frame work for studying WMN performance but also gives an insight into the design strategy for WMN gateway.

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“…In order to obtain the SNR input metric range for a WLAN, the SNR Range value was assumed to be from 10 to 50dB, based on a study conducted by [14]. Thus, in the proposed INS scheme, moving vehicles continuously monitored the SNR to ensure that the SNR level of the current and target networks were in the acceptable level.…”

Section: Intelligent Network Selection (Ins) Scheme Modementioning

confidence: 99%

An Intelligent Vertical Handover Scheme for Audio and Video Streaming in Heterogeneous Vehicular Networks

et al. 2013

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In heterogeneous vehicular networks, the most challenging issue is obtaining an efficient vertical handover during the vehicle roaming process. Efficient network selection process can achieve satisfactory Quality-of-Service for ongoing applications. In this paper, we propose an Intelligent Network Selection (INS) scheme based on maximization scoring function to efficiently rank available wireless network candidates. Three input parameters were utilized to develop a maximization scoring function that collected data from each network candidate during the selection process. These parameters are: Faded Signal-to-Noise Ratio, Residual Channel Capacity, and Connection Life Time. The results show that the proposed INS scheme is more efficient at decreasing handover delays, End-to-End delays for VoIP and Video applications, packet loss ratios as well as increasing the efficiency of network selection processes in comparison with the state of the arts.

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Analysis of the Relationship between QoS and SNR for an 802.11g WLAN

Cited by 9 publications

References 8 publications

Avaliação da Qualidade de uma Comunicação VoIP em uma rede WLAN real com diferentes Modelos de Desvanecimento

Avaliação da Qualidade de uma Comunicação VoIP em uma rede WLAN real com diferentes Modelos de Desvanecimento

Design of gateway locations in an indoor WMN

An Intelligent Vertical Handover Scheme for Audio and Video Streaming in Heterogeneous Vehicular Networks

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