Issue of this diploma thesis is focused on analysis of audio codecs used within IP telephony. Attention of teoretical part is given mostly to audio codecs according to ITU-T recommendations, but also to signaling protocols used here. For practical part of analysis is chosen router Cisco 2821 and IP phones Cisco 7975G. Configuration is done over operating system Cisco IOS. Chosen signaling protocol is SCCP. For analysis itself are chosen 2 analysers – L-580FX and Fluke NetTool. These are used in combination with program Wireshark. Analysed parameters are latency, packet lost, bandwidth, jitter and mean opinion score. Measured values are presented in graphs and tables and they are discussed. Next output of the thesis is laboratory excercise, which deals with analysis of audio codecs.

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To support the continuously increasing number of mobile telephone users around the world, mobile communication systems have become more advanced and sophisticated in their designs. As a result of the great success with the second generation mobile radio networks, deployment of the third and development of fourth generations, the demand for higher data rates to support available services, such as internet connection, video telephony and personal navigation systems, is ever growing. To be able to meet the requirements regarding bandwidth and number of users, enhancements of existing systems and introductions of conceptually new technologies and techniques have been researched and developed. Although new proposed technologies in theory provide increased network capacity, the backbone of a successful roll-out of a mobile telephone system is inevitably the planning of the network’s cellular structure. Hence, the fundamental aspect to a reliable cellular planning is the knowledge about the physical radio channel for wide sets of different propagation scenarios. Therefore, to study radio wave propagation in typical Australian environments, the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the Australian Telecommunications Cooperative Research Centre (ATcrc) in collaboration developed a cellular code division multiple access (CDMA) pilot scanner. The pilot scanner measurement equipment enables for radio wave propagation measurements in available commercial CDMA mobile radio networks, which in Australia are usually deployed for extensive rural areas. Over time, the collected measurement data has been used to characterise many different types of mobile radio environments and some of the results are presented in this thesis. The thesis is divided into an introduction section and four parts based on peer-reviewed international research publications. The introduction section presents the reader with some relevant background on channel and propagation modelling. Also, the CDMA scanner measurement system that was developed in parallel with the research results founding this thesis is presented. The first part presents work on the evaluation and development of the different revisions of the Recommendation ITU-R P.1546 point-to-area radio wave propagation prediction model. In particular, the modified application of the terrain clearance angle (TCA) and the calculation method of the effective antenna height are scrutinized. In the second part, the correlation between the smallscale fading characteristics, described by the Ricean K-factor, and the vegetation density in the vicinity of the mobile receiving antenna is investigated. The third part presents an artificial neural network (ANN) based technique incorporated to predict path loss in rural macrocell environments. Obtained results, such as prediction accuracy and training time, are presented for different sized ANNs and different training approaches. Finally, the fourth part proposes an extension of the path loss ANN enabling the model to also predict small-scale fading characteristics.

Orientador: Gelio Mendes Ferreira / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Engenharia da Informação, 2011

Progressive download video services, such as YouTube and podcasts, are responsible for a major part of the transmitted data volume in the Internet and it is expected, that they will also strongly affect mobile networks. Streaming video quality mainly depends on the sustainable throughput achieved during transmission. To ensure acceptable video quality in mobile networks (with limited capacity resources) the perceived quality by the customer (QoE) needs to be monitored by estimation. For that, the streaming video quality needs to be measured and monitored permanently. For TCP based progressive download we propose to extract the the video timestamps which are encoded within the payload of the TCP segments by decoding the video within the payload. The actual estimation is then done by play out buffer fill level calculations based on the TCP segment timestamp and their internal play out timestamp. The perceived quality for the user is derived from the number and duration of video stalls. Algorithms for decoding Flash Video, MP4 and WebM Video have already been implemented. After deriving the play out time it is compared to the timestamp of the respective TCP segment. The result of this comparison is an estimate of the fill level of the play out buffer in terms of play out time within the client. This estimation is done without access to the end device. The same measurement procedure can be applied for any TCP based progressive download Internet service. Video was simply taken as an example because of its current large share in traffic volume in operator networks.

Progressive download video services, such as YouTube, are responsible for a major part of the transmitted data volume in the Internet and it is expected, that they also will strongly affect mobile networks. Streaming video quality mainly depends on the sustainable throughput achieved during transmission. In order to achieve an acceptable video quality in mobile networks (with limited capacity resources), traffic engineering mechanisms have to be applied. For that, the streaming video quality needs to be measured and monitored permanently. Therefore, the video timestamps which are encoded within the payload of the TCP segments have to be extracted. For that it is necessary to decode the video within the transported payload. Algorithms for decoding Flash Video, MP4 and WebM Video have already been implemented as a demonstration implementation in support of the network based measurement contribution to SG12 by Chemnitz University for TCP encoded progressive download Internet services. In the demonstration, the derived play out buffering from the monitored traffic is being output internally. A second application is then used to graphically display the estimation result. The measurement and estimation is solely done within a measurement point of an operator network without access to the client’s end device.

VHF står för "Very High Frequency" och är ett frekvensband som ligger i området 30 - 300 MHz. Maritim VHF är standard för Sjöfartsverket och fungerar över hela världen. Det är ett kommunikationssystem som bidrar till ökad säkerhet och kan rädda liv på sjön. Andra vanliga kommunikationssystem som mobiltelefoni fungerar inte tillförlitligt. Idag fungerar mobiltelefoni i stora delar av skärgården och längs kusterna men när det gäller kommunikation mellan fartyg längre ut till havs är den maritima VHF-kommunikationen överlägsen. Sjöfartsverket driver för sitt eget och kunders behov ett mobilradionätverk kallat kustradionätverket. Radiotrafiken i nätet sker både på Very High Frequency (VHF) och Medium frequency (MF). VHF-systemet är ett internationellt system som bland annat används till att kommunicera till sjöss och den trafiken befinner sig i frekvensbandet 155.5 - 162.025 MHz. Inom VHF-bandet finns det 55 kanaler. Kanalerna vid kustradiostationen kallas för duplexkanaler och innebär att kustradiostationerna sänder och tar emot signaler på två olika frekvenser. Radioutbredningen hos antennen som är installerad på basstationen har riktverkan i vissa riktningar och dämpningar i andra. Detta kan ses i strålningsdiagrammet under kapitlet "Täckningsmodell" och avsnittet antennen. Andra faktorer som kan påverka radioutbredningen är förluster i basstationenssystemet, topologin hos området mellan sändare och mottagare samt väderberoende utbredningsegenskaper. Genom att hitta de tänkbara faktorer som påverkar signalutbredningen kan en täckningsmodell förutses. Det är förluster som finns i basstationen, radiolänken samt förluster vid mottagarantennen.

Made available in DSpace on 2016-12-23T13:56:10Z (GMT). No. of bitstreams: 1 Dissertacao de Ana Raquel Farranha Santana Daltro.pdf: 655316 bytes, checksum: 520ba803452b868f1e86dfd359960936 (MD5) Previous issue date: 2011-08-19 / Introduction Urinary tract infection is reported to affect 2 to 10% of all pregnancies. It is associated with maternal and neonatal complication including premature labor, premature rupture of membranes, low birth weight, intrauterine growth restriction, high perinatal mortality, maternal anemia, maternal and neonatal sepsis, arterial hypertension and renal failure. Objectives: To describe the prevalence of urinary tract infection, to identify etiologic agents and to describe the risk factors amongst pregnant women attending to a high risk antenatal clinic in Serra, Espiríto Santo. Methodology: Cross-sectional study of parturient women giving birth at Hospital Dr Dório Silva Maternity in the period between march 2010 and February 2011. The study collected information using face to face interviews including socio-demographics, epidemiologic and clinical data. The data collected included age, years of schooling, marital status, dwelling place, profession, number of pregnancies and abortions, type of delivery, gestational age and any previous history of urinary tract infection. A sample of urine was also collected and submitted to test1, urine culture and test sensibility antibiotic. Descriptive statistics analysis was performed. Any possible association between urinary tract infection and independent variables were tested using chi-square test with Yates correction or Fisher s exact test. Odds ratio and confidence intervals were calculated and a multivariate logistic regression analysis was used. Results: From 324 pregnant women identified, 305 (94.1%) took part in the study. The prevalence of urinary tract infection amongst the participants was 15.1% (CI 95% 11.0%-19.1%). The median age was 25 (DIQ 20; 30), years of schooling was 9 years (DIQ 7; 11). Fifty nine pregnant women (19.0%) were under 20, twenty eight (9.2%) had up to 4 years of formal education, two hundred and fifty five (83.6%) were married and one hundred and fifty five (50.8%) had a family income of less than 2 minimum wage. One hundred and twenty five (41.0%) were primigravidae, one hundred and seventy three (56.9%) were under 35 weeks when hospitalized and seventy five (24.6%) delivered low birth weight babies. Amongst the morbidities in the study 14.1% presented pre-eclampsy and 6.2% diabetes mellitus. Amongst the forty six cases of urinary tract infection, we identified twenty six with abnormal examination of urine sediment, with twenty three cases presenting pyuria. Four tests returned positive nitrite and twenty six tests presented increased bacterial flora. The agent isolated more frequently in the culture was Escherichia coli (52%), followed by Klebsiella sp. (15.2 %). Conclusion: The prevalence of urinary tract infections amongst the pregnant women cared for in the high risk maternity in Serra was high. These results corroborate the importance of screening for urinary tract infection during pregnancy in order to avoid complications during gestation and childbirth / Introdução: A Infecção urinária na gravidez tem prevalência de cerca de 2 a 10%. No ciclo gravídico ela pode causar parto pré-termo, amniorrexe prematura, recém nascidos de baixo peso, restrição do crescimento intra uterino, altas taxas de mortalidade perinatal, anemia materna, sepse materna e neonatal, hipertensão arterial sistêmica e insuficiência renal. Objetivos: Descrever a frequência da infecção do trato urinário, identificar agentes etiológicos e descrever fatores de associação para infecção em parturientes atendidas em maternidade de alto risco em Serra, Espírito Santo. Metodologia: Estudo de corte transversal em amostra quantitativa de parturientes internadas na maternidade do Hospital Dr Dório Silva, no período de março de 2010 a fevereiro de 2011. As informações utilizadas no estudo foram obtidas por meio de uma entrevista face-a-face contendo dados sócio-demográficos, epidemiológicos e clínicos, tais como: idade, escolaridade, estado civil, residência, profissão, número de gestações e abortos, tipo de parto, idade gestacional, e história anterior de infecção urinária. Foi coletada uma amostra de urina para realização de exame de urina tipo 1, urocultura e teste de sensibilidade ao antibiótico. Foi realizada análise estatística descritiva. As possíveis associações entre infecção do trato urinário e variáveis independentes foram testadas por meio de testes de qui-quadrado com correção de Yates ou teste Exato de Fisher. OddsRatio e intervalos de confiança foram calculados e análise multivariada de regressão logística foi utilizada. Resultados Do total de 324 gestantes selecionadas, 305 (94,1%) participaram do estudo. A prevalência de ITU foi 15,1% (IC95% 11,0%-19,1%). A mediana de idade foi 25 anos (DIQ 20; 30) e a de escolaridade foi 9 anos (DIQ 7; 11). Cinquenta e nove parturientes (19,0%) tinham menos de 20 anos, 28 (9,2%) tinham até 4 anos de estudo, 255 (83,6%) eram casadas e em 155 (50,8%) a renda familiar era menor do que dois salários mínimos. Cento e vinte cinco (41,0%) eram primigestas, 173 (56,9%) tinham menos de 35 semanas de gestação no momento da internação e 75 (24,6%) tiveram recém-nascidos de baixo peso. Entre as morbidades descritas, 14,1% tinham Doença Hipertensiva Específica da Gestação (DHEG) e 6,2% diabetes mellitus . Entre os 46 casos de infecção urinária, o EAS estava alterado em 26 casos, apresentando-se com piúria em 23 . Quatro exames apresentavam nitrito positivo e 26 exames apresentavam flora bacteriana aumentada. O agente isolado mais frequentemente na cultura foi a Escherichia coli (52%), seguida pela Klebsiella sp.(15,2%). Conclusão: A frequência de infecção do trato urinário em parturientes atendidas em maternidade de alto risco em Serra foi alta. Esses resultados corroboram a importância do rastreamento da ITU na gestação a fim de evitar complicações no ciclo gravídico -puerperal

Orientador: Silvia Hunold Lara / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Filosofia e Ciencias Humanas / Made available in DSpace on 2018-07-24T14:18:07Z (GMT). No. of bitstreams: 1 Ricci_MagdaMariadeOliveira_D.pdf: 16739457 bytes, checksum: 2267d2b161fec02d757f669c95cbdeb0 (MD5) Previous issue date: 1998 / Resumo: Não informado. / Abstract: Not informed. / Doutorado / Doutor em História

This Master Thesis report was written by Umeå University Engineering Physics student Richard Tano during his thesis work at Ericsson Luleå. Monitoring network quality is of utmost importance to network providers. This can be done with models evaluating QoS (Quality of Service) and conforming to ITU-T Recommendations. When determining video stream quality there is of more importance to evaluatethe QoE (Quality of Experience) to understand how the user perceives the quality. This isranked in MOS (Mean opinion scores) values. An important aspect of determining the QoEis the video content type, which is correlated to the coding complexity and MOS values ofthe video. In this work the possibilities to improve quality estimation models complying to ITU-T study group 12 (q.14) was investigated. Methods were evaluated and an algorithm was developed that applies time series analysis of packet statistics for determination of videostreams MOS scores. Methods used in the algorithm includes a novel assembling of frequentpattern analysis and regression analysis. A model which incorporates the algorithm for usage from low to high bitrates was dened. The new model resulted in around 20% improvedprecision in MOS score estimation compared to the existing reference model. Furthermore an algorithm using only regression statistics and modeling of related statistical parameters was developed. Improvements in coding estimation was comparable with earlier algorithm but efficiency increased considerably. / Detta examensarbete skrevs av Richard Tano student på Umeå universitet åt Ericsson Luleå. Övervakning av nätets prestanda är av yttersta vikt för nätverksleverantörer. Detta görs med modeller för att utvärdera QoS (Quality of Service) som överensstämmer med ITU-T rekommendationer. Vid bestämning av kvaliten på videoströmmar är det mer meningsfullt att utvärdera QoE (Quality of Experience) för att få insikt i hur användaren uppfattar kvaliten. Detta graderas i värden av MOS (Mean opinion score). En viktig aspekt för att bestämma QoE är typen av videoinnehåll, vilket är korrelerat till videons kodningskomplexitet och MOS värden. I detta arbete undersöktes möjligheterna att förbättra kvalitetsuppskattningsmodellerna under uppfyllande av ITU-T studygroup 12 (q.14). Metoder undersöktes och en algoritm utvecklades som använder tidsserieanalys av paketstatistik för uppskattning av videoströmmars MOS-värden. Metoder som ingår i algoritmen är en nyutvecklad frekventa mönster metod tillsammans med regressions analys. En modell som använder algoritmen från låg till hög bithastighet definierades. Den nya modellen gav omkring 20% förbättrad precision i uppskattning av MOS-värden jämfört med existerande referensmodell. Även en algoritm som enbart använder regressionsstatistik och modellerande av statistiska parametrar utvecklades. Denna algoritm levererade jämförbara resultat med föregående algoritm men gav även kraftigt förbättrad effektivitet.