Orientador: Michel Daoud Yacoub / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-23T14:27:26Z (GMT). No. of bitstreams: 1 Heinrich_RalphRobert_M.pdf: 7113070 bytes, checksum: 2a64f903bc44fb31b9ee53ef545bb24e (MD5) Previous issue date: 2013 / Resumo: Este projeto de pesquisa objetiva responder a algumas questões sistêmicas levantadas por ocasião do início do desenvolvimento do sistema LTE-450, parte integrante do projeto RASFA - Redes de Acesso Sem Fio Avançadas, conduzido pelo CPqD - Fundação Centro de Pesquisa e Desenvolvimento em Telecomunicações, com recursos do FUNTTEL - Fundo para o Desenvolvimento Tecnológico das Telecomunicações. Esse projeto visa, como um de seus objetivos, o desenvolvimento de um sistema de rádio acesso sem fio LTE-450, operando na faixa de 450 a 470 MHz, baseado na tecnologia LTE - Long Term Evolution. A faixa de 450 a 470 MHz está atribuída em base global desde 2007 para o Serviço Móvel, conforme identificado pela União Internacional de Telecomunicações na World Radiocommunication Conference 2007. A Anatel - Agência Nacional de Telecomunicações - publicou a nova destinação de uso para a faixa de 450 a 470 MHz em 20 de dezembro de 2010, através da Resolução n º 558. Várias ações vêm sendo empreendidas em apoio ao uso da faixa 450 a 470 MHz, para a prestação de serviços banda larga sem fio para áreas rurais, como consta do Programa Nacional de Telecomunicações Rurais, publicado pela Portaria 431/2009 do Ministério das Comunicações, e do Plano Nacional de Banda Larga, publicado em 13 de maio de 2010. Entende-se que a faixa de 450 a 470 MHz é ideal para a implantação de serviços de banda larga sem fio em áreas rurais, devido às suas características de propagação. Por outro lado, a base de conhecimento sobre o canal rádio em sistemas de rádio acesso móvel banda larga considera o uso, em áreas urbanas, de faixas de frequências situadas entre 850 MHz e 3500 MHz. São notórias as diferenças entre as características de propagação nessas faixas e nas faixas de UHF, principalmente quando a área de prestação do serviço deixa de ser a urbana e passa a ser a rural. Nesse sentido, alguns requisitos sistêmicos podem ser questionados e mesmo redimensionados. Esses requisitos foram aqui endereçados através de levantamento de dados em campo e posterior análise crítica contra a base de conhecimento disponível. São questões como a amplitude do desvanecimento seletivo e por despolarização, a intensidade do ruído impulsivo, os modelos de propagação aplicáveis à área rural e à faixa de UHF, a variação da perda de percurso com a altura da antena do terminal e a discriminação de polarização da antena do terminal / Abstract: This research project aims to answer some systemic issues raised during the early development of the LTE-450 radio access system, part of a project RASFA - Advanced Wireless Networks Access, led by CPqD Foundation - Center for Research and Development in Telecommunications with resources of FUNTTEL - Technological Development of Telecommunications Fund. This project aims, as one of its objectives, the development of a LTE-450 wireless system, operating in the 450-470 MHz band, based on LTE - Long Term Evolution technology. The 450-470 MHz band is allocated, on a global basis, since 2007 for Mobile Service, as identified by the International Telecommunication Union in the World Radiocommunication Conference 2007. Anatel - The Brazilian National Telecommunications Agency has published a new destination for the 450-470 MHz band on December 20, 2010, through Resolution No. 558. Several actions have been undertaken in support of the use of the 450-470 MHz band, to provide wireless broadband services to rural areas, as set out in the National Rural Telecommunications Plan, published by the Decree 431/2009 of the Ministry of Communications and the National Broadband Plan (PNBL), published on May 13, 2010. It is understood that the 450-470 MHz band is ideal for deploying wireless broadband services in rural areas, due to its propagation characteristics. On the other hand, the base of knowledge about the mobile broadband access radio systems channel, considering the use in urban areas, situated between 850 MHz and 3500 MHz bands have notable differences between the propagation characteristics of these bands and the UHF bands, especially when the area of service provision ceases to be the urban and goes to the rural areas. Thus, some systemic requirements can be questioned and even resized. These requirements are addressed here through field data gathering and subsequent critical analysis against the knowledge base available. These issues are such as the extent of selective fading and depolarization, the intensity of the impulse noise, the propagation models applicable to the rural area and the UHF band, the variation of the path loss with the height of the terminal antenna and of terminal antenna polarization discrimination / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica

Orientador: Celso de Almeida / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-19T04:16:05Z (GMT). No. of bitstreams: 1 MoyaOsorio_DianaPamela_M.pdf: 1282063 bytes, checksum: 0bd5600058b4051f103c6622f93e5cc4 (MD5) Previous issue date: 2011 / Resumo: Na próxima geração de redes celulares, a ICC (Interferência de Co-Canal ) constitui a causa principal para a degradação do desempenho, especialmente para os usuários na borda da célula, o que é um grande obstáculo para alcançar amplas áreas de cobertura e alta eficiência espectral. Neste trabalho, o desempenho do enlace reverso de uma rede celular em termos da eficiência espectral média e na presença de ICC é avaliado mediante uma simulação semi-analítica. Foram considerados dois cenários, canal AWGN(Additive White Gaussian Noise) e canal com desvanecimento plano do tipo Rayleigh, além de um modelo de propagação com perda de percurso exponencial. A avaliação é feita para fatores de reuso clássicos e modulações M-QAM (Multi-Level Quadrature Amplitude Modulation). Considera-se também uma estratégia de controle de potência e modulação adaptativa baseada na SIR (Signal-to-Noise Interference) e a BER (Bit Error Rate). Adicionalmente, é analisada a utilização de arranjo de antenas para diminuição dos efeitos da interferência e técnicas de diversidade para mitigação dos efeitos do desvanecimento / Abstract: In the next generation of wireless cellular networks, the CCI (Co-Channel Interference) constitutes the primary cause of performance degradation, specially for cell edge users, which is a big obstacle to attain wide area coverage and high spectral efficiency. In this work, the performance of the uplink of cellular networks in terms of the mean spectral efficiency is evaluated through a semi-analytical simulation, by considering the presence of CCI. It was considered two sceneries, an AWGN (Additive White Gaussian Noise) channel and a Rayleigh flat fading channel, as well as an exponential pathloss propagation model. The evaluation is done for classical reuse factors and M-QAM (Multi-Level Quadrature Amplitude Modulation) modulations. It is also considered a power control strategy and adaptive modulation based on the SIR (Signal-to-Noise Interference) and BER (Bit Error Rate). Besides, it is analyzed the utilization of an antenna array to reduce the interference effects and diversity techniques to mitigate fading effects / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica

Wireless technologies, such as Worldwide Interoperability for Microwave Access (WiMAX) and Wireless Fidelity (WiFi), are making it easier to provide the much needed telecommunications infrastructure in marginalized areas worldwide. These technologies enable the rapid deployment of network services as well as their redistribution throughout these marginalized areas. The ability to bring Internet connectivity to previously underserviced and marginalized areas has the potential to leap-frog socio-economic development and improve participation in the global knowledge economy. This study investigated how wireless access technologies, such as WiMAX and WiFi, can be integrated and used to deliver ubiquitous distributed Internet connectivity with increased capillarity in rural areas. The research was undertaken within an ICT for Development (ICT4D) intervention called Siyakhula Living Lab (SLL) which is based in the Eastern Cape province of South Africa. The research further eliminated the accessibility constraints associated with long distances and remoteness from the Digital Access Nodes (DANs) and provided increased penetration in the network in contrast to the traditional Telecentre model which has been used extensively in ICT4D interventions. This was achieved by deploying WiFi hotspots around the DANs and extending the existing SLL WiMAX backbone to increase the network footprint to neighboring communities. The technical result of the research has been the provision of increased capillarity on the network and service redistribution throughout the entire Dwesa community. Consequently, this has given local community members an opportunity to access network services easily and ubiquitously. Finally, the research investigated and presented the benefits of such wireless network deployment configurations on ICT4D activities in marginalized areas.

No description available.

Hybrid Wireless Networks (HWNs) are composite networks comprises of different technologies, possibly with overlapping coverage. Users with multimode terminals in HWNs are able to initiate connectivity that best suits their attributes and the requirements of their applications. There are many complexities in hybrid wireless networks due to changing data rates, frequency of operation, resource availability, QoS and also, complexities in terms of mobility management across different technologies. A superstore is a very large retail store that serves as a one-stop shopping destination by offering a wide variety of goods that range from groceries to appliances. It provide all types services such as banking, photo center, catering, etc. The good examples of superstores are: Tesco (hypermarkets, United Kingdom), Carrefour(hypermarkets, France), etc. Generally, the mobile customer communicates with superstore server using a transaction. A transaction corresponds to a finite number of interactive processes between the customer and superstore server. A few superstore transactions, examples are, product browsing, Technical details inquiry, Financial transactions, billing, etc. This thesis aims to design and develop the following schemes to solve some of the above indicated problems of a hybrid wireless superstore network: 1 Transaction based bandwidth management. 2 Transaction-based resource management. 3 Transaction-based Quality of Service management. 4. Transactions-based topology management. We, herewith, present these developed schemes, the simulation carried out and results obtained, in brief. Transaction-based bandwidth management The designed Transaction-Based Bandwidth Management Scheme (TB-BMS) operates at application-level and intelligently allocates the bandwidth by monitoring the profit oriented sensitivity variations in the transactions, which are linked with various profit profiles created over type, time, and history of transactions. The scheme mainly consists of transaction classifier, bandwidth determination and transactions scheduling modules. We have deployed these scheme over a downlink of HWNs, since the uplink caries simple quires from customers to superstore server. The scheme uses transaction scheduling algorithm, which decides how to schedule an outgoing transaction based on its priority with efficient use of available BW. As we observe, not all superstore transactions can have the same profit sensitive information, data size and operation type. Therefore, we classify the superstore transactions into four levels based on profit, data size, operation type and the degree of severity of information that they are handling. The aim of transaction classification module is to find the transaction sensitivity level(TSL) for a given transaction. The bandwidth determination module estimates bandwidth requirement for each of the transactions. The transactions scheduling module schedules the transactions based on availability of bandwidth as per the TSL of the transaction. The scheme schedules the highest priority transactions first, keeping the lowest priority transaction pending. If all the highest priority transactions are over, then it continues with next priority level transactions, and so on, in every slot. We have simulated the hybrid wireless superstore network environment with WiFi and GSM technologies. We simulated four TSL levels with different bandwidth. The simulation under consideration uses different transactions with different bandwidth requirements. The performance results describe that the proposed scheme considerably improves the bandwidth utilization by reducing transaction blocking and accommodating more essential transactions at the peak time of the business. Transaction-based resource management In the next work, we have proposed the transaction-based resource management scheme (TB-RMS) to allocate the required resources among the various customer services based on priority of transactions. The scheme mainly consists of transaction classifier, resource estimation and transactions scheduling modules. This scheme also uses a downlink transaction scheduling algorithm, which decides how to schedule an outgoing transaction based on its priority with efficient use of available resources. The transaction-based resource management is similar to that of TB-BMS scheme, except that the scheme estimates the resources like buffer, bandwidth, processing time for each of transaction rather than bandwidth. The performance results indicate that the proposed TB-RMS scheme considerably improves the resource utilization by reducing transaction blocking and accommodating more essential transactions at the peak time. Transaction-based Quality of Service management In the third segment, we have proposed a police-based transaction-aware QoS management architecture for the downlink QoS management. We derive a policy for the estimation of QoS parameters, like, delay, jitter, bandwidth, transaction loss for every transaction before scheduling on the downlink. We use Policy-based Transaction QoS Management(PTQM) to achieve the transaction based QoS management. Policies are rules that govern a transaction behavior, usually implemented in the form of if(condition) then(action) policies. The QoS management scheme is fully centralized, and is based on the ideas of client-server interaction. Each mobile terminal is connected to a server via WiFi or GSM. The master policy controller (MPDF) connects to the policy controller of the WiFi network (WPDF)and the GSM policy controller(PDF). We have considered the simulation environment similar to earlier schemes. The results shows that the policy-based transaction QoS management is improves performance and utilizes network resources efficiently at the peak time of the superstore business. Transactions-Aware Topology Management(TATM) Finally, we have proposed a topology management scheme to the superstore hybrid wireless networks. A wireless topology management that manages the activities and features of a wireless network connection. It may control the process of selecting an available access points, authentication and associating to it and setting up other parameters of the wireless connection. The proposed topology management scheme consists of the transaction classifier, resource estimation module, network availability and status module and transaction-aware topology management module. The TATM scheme is to select the best network among available networks to provide transaction response(or execution). We have simulated hybrid wireless superstore network with five WiFi and two GSM technologies. The performance results indicate that the transaction-based topology management scheme utilizes the available resources efficiently and distributed transaction loads evenly in both WiFi and GSM networks based on the capacity.

The study investigated the use of mobile phones in disseminating information on agriculture to the farming community of Mashonaland West Province of Zimbabwe, with a view to improving the coverage gap created by the available initiatives. Relevant literature on the available and successful mobile phones agricultural information dissemination platforms were extensively reviewed, taking into consideration the Mashonaland West Province farmers’ information needs. Formats, channels and sources currently being used to transmit agricultural information to farmers were investigated. Barriers to the use of mobile phones in transmitting agricultural information were as well investigated. Data was gathered on the farmers’ access to mobile phones and ownership of mobile phones. The survey research methodology was used for data collection because the research involved a large sample in a widespread geographical area. Quantitative research approach was used and questionnaires were used for data collection. The respondents for the study comprised farmers, network providers and other agricultural stakeholders in the province. A sample of 384 farmers, and 13 network providers and other stakeholders participated in the survey. Quantitative data was analysed using the the SPSS software while the little qualitative data which was available was analysed through content analysis. The findings of the study indicated that farmers in Mashonaland West Province of Zimbabwe were willing to get updates on agricultural information via cell phones. However, majority of the farmers could not afford the high mobile data tariffs being charged by network service providers, and the costs of subscription charged by the available agricultural information dissemination platforms. The study mainly recommended that the government should establish mobile phone agricultural information dissemination platforms that can be accessed by farmers for free or that which will charge affordable rates. The study adds to the existing knowledge on how mobile phones can be used in disseminating agricultural information to farmers. / Information Science / D. Inf. (Information Science)

Software orchestrators like Kubernetes are growing in popularity with computer engineers for deploying and running complex software systems. Interestingly, there are now new technical standards being proposed for the telecom industry to begin utilizing software orchestration for the software that runs inside cellular networks. The telecom industry is currently transitioning from 4G to 5G technology. One of the central pieces of this development work is implementing a software orchestrator for 5G networks. This raises some questions about how and why the telecom industry will use software orchestration in their cellular networks. Software orchestration is a complex technology and it is challenging to develop an implementation of a software orchestrator. Some important questions that this thesis addresses are: What do network operators need from this technology? Furthermore, telecom vendors, like Ericsson and Huawei, have developed their own versions of a 5G software orchestrator, which orchestrator should the network operators choose? Furthermore, we investigate what 5G is, why the telecom industry is developing software orchestrators for the 5G roll-out, and importantly, we determine the design requirements that the telecom industry has for these "5G orchestration systems". We interpret and break down technical whitepapers from the industry, and we build a picture of the IT stack of upcoming 5G networks. In our research, we find that software orchestration is being used to deploy and maintain complex software stacks such as software-defined networking (SDN) system that is central to 5G networks. We uncover some of the specializations needed in a software orchestrator for the telecom industry, such as modularity, high-availability, and specialized system integration. With this information, we make feature and design recommendations for 5G orchestrators, and we compile a list of criteria that network operators can use to assess and compare different 5G orchestrators. / Orkestreringsprogramvaror som Kubernetes växer i popularitet med IT ingenjörer för att installera och köra komplexa mjukvarasystem. På grund av pågående transitionen från 4G till 5G, används orkestreringsprogramvaror nu också i mobilnäten. I den här uppsatsen undersöks vad är 5G, varför telekombranschen använder orkestreringsprogramvaror för nya 5G nätverk, och vad krav har telekombranschen på denna "5G orkestreringsprogramvaror". Denna undersökning utförs genom en litteraturstudie. Genom den här undersökningen, det visar sig att orkestreringsprogramvaror används för att installera och köra komplexa mjukvarasystem som är centralt till 5G nätverk. Specialiseringskrav för orkestreringsprogramvaror i telekombranschen upptäcks, som modularitet, hög tillgänglighet, och specialiserad API-hookar. Rekommendationer görs för 5G orkestreringsprogramvarors funktioner, och en lista sammanställas av kriterier som telekomoperatör kan använda för att bedöma och jämföra 5G orkestreringsprogramvaror.

The use of cellphones has increased all over the world. That invites many academics to conduct research on the usage of these devices, especially by young people, since young people join Social Network Sites (Facebook, Mxit, 2go, Whatsapp) and use a shorthand language. Most studies are related to the use of English and other languages that are recognised by computer software. There are few studies, if any, that have been done in relation to the use of African Languages on these sites. This research therefore aims to seek to explore the use of African Languages, especially isiXhosa, in assessing how technology might help in language development through the usage of SNSs that learners already use to equip them with educational material in their mother tongue. This study was conducted in two high schools, Nogemane Senior Secondary School in a disadvantaged and remote rural community with limited access to additional educational material such as magazines, newspapers, and television. The school also lacks basic study materials such as textbooks from the Education Department and they have no access to a library and laboratory. They also only have very few subjects to choose from. Nombulelo Senior Secondary School is in Grahamstown. This school has good infrastructure and learners have access to different technological devices and they can access libraries. What is common between learners in both schools is that they are all doing isiXhosa as a first language and are using SNSs to interact with each other. This study has found that learners enjoy using SNSs rather than reading the printed books. Furthermore, they enjoy and prefer interacting in isiXhosa in their conversations. Learners also use the web to post and show their creative writing, regardless of the shorthand form writing they use on the SNSs. This study has found that learners are not well equipped with basic isiXhosa skills when reaching the FET phase. They lack the understanding of standard isiXhosa idioms and proverbs. That clearly means that they are equipped in the more modern forms of literature rather than the traditional oral forms. IsiXhosa teachers also see SNSs as the better platform to engage with learners and they suggest that there must be a section in the subjects at school that teaches about cyber bullying and being safe online. This thesis also presents examples of new and contemporary forms of SNS-speak that are used by learners in both the rural and urban schools. This study is more concerned with SNSs for literacy development and to assess whether the shorthand writing has negative or positive effects in writing isiXhosa. This is done against the backdrop of a literature review which explores new literacies, computer mediated communication, social identity models as well as language policy and planning.

It is sincerely hoped that this work will motivate other researchers and in particular my colleagues to do further research in the field of cellphone technology, especially how it can be mapped to enable it to be utilised as evidence in our courts. This research aims to develop the mapping of cellphone technology as an aid in the investigation of crime. The mapping of cellphone technology refers to how cellphone technology can be utilised in crime investigation and in particular how a criminal can be placed at the scene of a crime, as a result of a cellphone call that was either made or received. To place the suspect at the scene of a crime as a result of a call made or received, cellphone records and technology of the relevant cellphone company, as well as present computer programmes can be utilised. Shortly, it can be said that a criminal can geographically be placed within a space some where on this earth. / Criminology / M.Tech. (Forensic Investigation)

More than one billion people, almost one in six of the world's population, are now using GSM mobile phones. The situation in South Africa is no different from that in the rest of the world. The rise of mobile telephone usage in South Africa has been driven by a combination of factors such as demand, sector reform, the licensing of new competition, and the emergence of major strategic investors, such as Vodacom and MTN. It was estimated that by March 2005 there should be approximately 20 million cellular customers in South Africa. The growth in the South African cellular market is proportionate to the potential risks in an environment where organisations are continuously seeking ways of improving efficiency, cutting costs, and staying abreast of technological advances. Elements of risk control such as Safety, Health, and Environmental Management can no longer be left out of the equation while organisations in the GSM industry are considering increasing their networks to meet the demands of growth. Although risk assessments are not specifically defined in the Occupational Health and Safety Act (85 of 1993); Section 8 does, however, stipulate under the general duties of the employer that the employer must establish, as far as is reasonably practicable, which hazards to the health or safety of persons are attached to any work which is performed. This situation has changed with the promulgation of the Construction Regulations, GNR.1010 on 18 July 2003; which state that every contractor performing construction work shall, before the commencement of any construction work and during construction work, cause a risk assessment to be performed by a competent person appointed in writing, and that the risk assessment shall form part of the health and safety plan to be applied on the site. This requirement under the Construction Regulations will have a major impact on organisations in the GSM industry. Integrated Health, Safety and Environmental risk assessments have now become a prerequisite before considering any further expansion of the GSM network in South Africa. The relationship between the operational risk sub-disciplines of health, safety, and environmental management, as part of the risk-management function, has been established, and an operational risk-assessment model for the Global Systems Mobile Telecommunications industry in South Africa that measures occupational health, safety, and environmental management risks on an integrated basis has been developed. The risk assessment model for the South African GSM industry is based on assessing the frequency of an activity in relation to the impact on the organisation's business processes, incident/accident potential, financial impact, legal status, and the nature of ecological impact. / Business Management / D. Com. (Business Management)