全球行動電話用戶數於2002年達到12億，首度超過固定電話用戶數之11億；行動電話用戶數並於2008年達41億，為固定電話用戶數(13億)之3倍以上。行動電話相對於固定電話之主要優勢在於系統之建置成本低及佈建速度快；行動電話之快速普及已成為創新擴散研究之重要題材。 行動電話擴散之研究為選取一成長模型(例如Gompertz、Logistic或Bass模型)並類比該模型以求出擴散之參數(例如成長速率)，以進一步(1)了解相關驅動因子(例如技術創新、市場開放等)對擴散參數之影響，及(2)延伸擴散模型曲線以預測未來之成長。 惟成長模型之選取尚無原理原則可供遵循而具隨機性(ad hoc basis)。為找出模型選用之可能規律，以降低模型選用之隨機性並提高成長預測之準確度，本研究以十二個代表性國家(巴、中、法、德、印、日、韓、俄、星、台、英、美)至2007年之資料以比較三個最常用之成長模型之績效，即Gompertz、Logistic及Bass模型。模型績效逐年比較標準係採用rmse值，並輔以Friedman test檢測模型績效差異之顯著性，再對照模型之機制意涵，以進一步了解最適模型之選用原則。 此外，台灣行動電話普及率於2002年為108%居全球之冠，而中國自2001年起取代美國成為全球具最多行動電話用戶數之單一國家，台灣及中國屬行動電話擴散之重要個案，惟目前尚缺此二個案之實證研究。為補足此一缺口，本研究亦對台灣及中國行動電話擴散之驅動因子進行實證研究，以進一步了解擴散之關鍵驅動力。 研究發現由於目前統計軟體之進步，Gompertz、Logistic及Bass三模型均可獲致極佳之匹配度而難分軒輊，惟模型預測力(延伸曲線)則具差異性。12個模型選用樣本國家中之8個國家(巴、中、法、德、日、韓、英、美)係以Gompertz模型具較佳之預測力；依Gompertz模型機制意涵，代表行動電話擴散早期係受網路外部性(口耳相傳)影響，惟至擴散後期(例如過了擴散極大值之一半)則已不相關。此外，若因市場開放等重大變因造成行動電話之快速擴散，則Logistic模型具有較佳之績效，如台灣及俄羅斯屬之。依Logistic模型機制意涵，代表擴散係受網路外部性所影響。Bass模型應用於行動電擴散時，因該模型所算出之創新係數偏低，績效與Logistic模型相近，而Logistic模型為Bass模型之創新係數為0時之特例。 台灣及中國行動電話擴散之驅動因子研究發現(1)價格下降及(2)預付卡之推行對加速擴散具顯著性，兩者均對低階市場之採用具影響力。鑑於高階市場將先飽和，爰未來加速行動電話擴散之關鍵驅動因子應係與推動低階市場採用具密切相關性。以中國為例，未來市場開放競爭造成價格再度大幅下降，將進一步促低階市場採用，加速中國行動電話之普及。 / The number of mobile telephone subscriptions reached 1.2 billion globally in 2002, exceeding fixed-line telephony subscriptions (1.1 billion) for the first time. The number of mobile telephone subscriptions reached 4.1 billion globally in 2008, over three times the number of fixed-line telephone subscriptions (1.3 billion). The main advantages of mobile telephony over fixed-line are low cost and rapid facility deployment. The rapid diffusion of mobile telephony has become an important topic in innovation diffusion. The conventional approach to studying mobile telephony diffusion is to analogize a single growth model, such as the Gompertz, Logistic or Bass model, and calculate the model parameters, for example growth rate. The significance of certain selected driving forces, such as technology innovation or market competition, to the studied parameters, such as growth rate, is then estimated. The diffusion growth can also be forecast by extrapolating the diffusion curve. Utilizing the growth model analogy is the first step in analyzing mobile telephony diffusion. However, no principles or rules exit for selecting a growth model. To identify rules for model selection to reduce randomness and increase forecast accuracy, this work uses 12 sample countries, namely Brazil, China, France, Germany, India, Japan, Korea, Russia, Singapore, Taiwan, the UK and the USA, employing data prior to 2008 to compare the performance of three most commonly used models, namely the Gompertz, Logistic and Bass models. The root mean square error (rmse) is chosen as the criterion for measuring annual model performance. The work uses the Friedman test to examine the significance of differences in performance between models. The implications of model mechanisms are emphasized to investigate the selection rule for the most appropriate model. The penetration of mobile telephony in Taiwan was 108% in 2002, ranking first in the world. Furthermore, in 2001 the number of mobile telephony in China replaced the United States as number one in the world. Both Taiwan and China are important examples for mobile telephony diffusion. However, no empirical investigation has been performed in these two cases. To fill this gap, this work estimated the driving forces for mobile telephony diffusion in Taiwan and China to learn about the critical drivers of the mobile telephony diffusion. Empirical results indicate that due to improvements in statistical software, providing good fitness for all three models, namely the Gompertz, Logistic and Bass models, distinguishing which has the best fitness is difficult. However, the performance of the three models is distinguishable when forecasting based on extrapolating the diffusion curve. In eight of the 12 examples, namely Brazil, China, France, Germany, Japan, Korea, the UK and the USA, the Gompertz model is the most appropriate model for forecasting. The mechanism of the Gompertz model means that during the initial stage the diffusion is correlated with network externalities (namely word of mouth), however, this correlation reduces during the later stages (such as pass one half of the maximum potential). Moreover, the cases of Taiwan and Russia demonstrated that the Logistic model performs well provided some significant driver of the diffusion exists. The mechanism of the Logistic model means that the diffusion is correlated with network externalities throughout the whole diffusion. Furthermore, using Chinese data, when the Bass model is applied, because of its low innovation coefficient, it performs similarly to the Logistic model, which is a special case of the Bass model in which the innovation coefficient equals zero. Empirical results for the critical driving forces of mobile telephony diffusion in Taiwan and China indicate that (1) reducing prices and (2) the launch of pre-paid services are crucial to mobile telephony diffusion. Both factors are essential to mobile telephony adoption in low-end markets. The high-end market is the first to be saturated by mobile telephony adoption, future drivers of the mobile telephony diffusion should be highly correlated with low-end market demand. Taking China as an example, the opening of the market to further reduce tariffs will attract mobile telephony adoption in the low-end market, facilitating the mobile telephony diffusion.

Submitted by Gisele Isaura Hannickel (gisele.hannickel@fgv.br) on 2012-04-24T18:53:49Z No. of bitstreams: 1 120423 Master Thesis FGV.pdf: 3697873 bytes, checksum: f3ccbecacf430eaee0f0606f9daa9f36 (MD5) / Approved for entry into archive by Eliene Soares da Silva (eliene.silva@fgv.br) on 2012-04-25T15:52:36Z (GMT) No. of bitstreams: 1 120423 Master Thesis FGV.pdf: 3697873 bytes, checksum: f3ccbecacf430eaee0f0606f9daa9f36 (MD5) / Made available in DSpace on 2012-04-25T15:54:46Z (GMT). No. of bitstreams: 1 120423 Master Thesis FGV.pdf: 3697873 bytes, checksum: f3ccbecacf430eaee0f0606f9daa9f36 (MD5) Previous issue date: 2012-04-23 / Internet Telephony (VoIP) is changing the telecommunication industry. Oftentimes free, VoIP is becoming more and more popular amongst users. Large software companies have entered the market and heavily invest into it. In 2011, for instance, Microsoft bought Skype for 8.5bn USD. This trend increasingly impacts the incumbent telecommunication operators. They see their main source of revenue – classic telephony – under siege and disappear. The thesis at hand develops a most-likely scenario in order to determine how VoIP is evolving further and it predicts, based on a ten-year forecast, the impact it will have on the players in the telecommunication industry.The paper presents a model combining Rogers’ diffusion and Christensen’s innovation research. The model has the goal of explaining the past evolution of VoIP and to isolate the factors that determine the further diffusion of the innovation. Interviews with industry experts serve to assess how the identified factors are evolving.Two propositions are offered. First, VoIP operators are becoming more important in international, corporate, and mobile telephony. End-to-end VoIP (IP2IP) will exhibit strong growth rates and increasingly cannibalize the telephony revenues of the classic operators. Second, fix-net telephony in SMEs and at home will continue to be dominated by the incumbents. Yet, as prices for telephony fall towards zero also they will implement IP2IP in order to save costs. By 2022, up to 90% of the calls will be IP2IP. The author recommends the incumbents and VoIP operators to proactively face the change, to rethink their business strategies, and to even be open for cooperation.

Made available in DSpace on 2014-12-17T14:55:48Z (GMT). No. of bitstreams: 1 FredSRP.pdf: 1871145 bytes, checksum: 9d94e1a0030a3d2f8d2aa6aaa2df93bd (MD5) Previous issue date: 2006-02-17 / The development of wireless telecommunication in the last years has been great. It has been taking academics to conceive new ideas and techniques. Their aims are to increase the capacity and the quality of the system s services. Cells that are smaller every time, frequencies that are every time higher and environments that get more and more complex, all those facts deserve more accurate models the propagation prediction techniques are inserted in this context and results with a merger of error that is compatible with the next generations of communication systems. The objective of this Work is to present results of a propagation measurement campaign, aiming at pointing the characteristics of the mobile systems covering in the city of Natal (state of Rio Grande do Norte, Brazil). A mobile laboratory was set up, using the infra-structure available and frequently used by ANATEL. The measures were taken in three different areas: one characterized by high buildings, high relief, presence of trees and towers of different highs. These areas covered the city s central zone, a suburban / rural zone and a section of coast surrounded by sand dunes. It is important to highlight that the analysis was made taking into consideration the actual reality of cellular systems with covering ranges by reduced cells, with the intent of causing greater re-use of frequencies and greater capacity of telephone traffic. The predominance of telephone traffic by cell in the city of Natal occurs within a range inferior to 3 (three) km from the Radio-Base Station. The frequency band used was 800 MHz, corresponding to the control channels of the respective sites, which adopt the FSK modulation technique. This Dissertation starts by presenting a general vision of the models used for predicting propagation. Then, there is a description of the methodology used in the measuring, which were done using the same channels of control of the cellular system. The results obtained were compared with many existing prediction models, and some adaptations were developed by using regression techniques trying to obtain the most optimized solutions. Furthermore, according to regulations from the old Brazilian Holding Telebr?s, a minimum covering of 90% of a determined previously area, in 90% of the time, must be obeyed when implanting cellular systems. For such value to be reached, considerations and studies involving the specific environment that is being covered are important. The objective of this work is contribute to this aspect / O enorme desenvolvimento das comunica??es sem fio tem levado estudiosos a conceber novas id?ias e t?cnicas visando aumentar a capacidade e melhorar a qualidade de servi?o dos sistemas de comunica??o m?vel. C?lulas cada vez menores, freq??ncias cada vez mais altas e ambientes cada vez mais complexos est?o a merecer modelamentos mais acurados e as t?cnicas de predi??o de propaga??o se inserem neste contexto, estando ainda a merecer resultados com margem de erro compat?vel com as pr?ximas gera??es de sistemas de comunica??o. Este trabalho tem por finalidade apresentar os resultados de uma campanha de medidas de propaga??o visando caracterizar a cobertura de sistemas m?veis celulares na cidade do Natal, RN. Um laborat?rio m?vel foi montado aproveitando a estrutura dispon?vel e utilizada rotineiramente pela ANATEL. As medi??es foram efetuadas em ?reas com caracter?sticas de edifica??es, relevo, arboriza??o e alturas de torres diversificadas, abrangendo a zona central da cidade, uma zona de caracter?stica suburbana / rural e trecho litor?neo circundado por dunas. ? importante destacar que a an?lise foi feita considerando a realidade atual dos sistemas celulares com raios de cobertura por c?lula reduzidos visando proporcionar maior reuso de freq??ncias e maior capacidade de tr?fego telef?nico. A predomin?ncia do tr?fego telef?nico por c?lula na cidade do Natal ocorre dentro de um raio inferior a 3 (tr?s) km em rela??o a Esta??o R?dio-Base. A faixa de freq??ncia utilizada foi de 800 MHz, correspondendo aos canais de controle dos respectivos sites, os quais adotam a t?cnica de modula??o FSK. Neste trabalho, apresenta-se inicialmente uma vis?o geral dos modelos utilizados para predi??o de propaga??o. Em seguida, descreve-se a metodologia utilizada nas medi??es, as quais foram efetuadas aproveitando os pr?prios canais de controle do sistema celular. Os resultados obtidos foram comparados com diversos modelos de predi??o existentes e foram desenvolvidas adapta??es utilizando t?cnicas de regress?o na tentativa de obten??o de solu??es mais otimizadas. Al?m disso, ? importante observar que, de acordo com norma da antiga holding brasileira Telebr?s, uma cobertura m?nima de 90% de uma ?rea pr?-estabelecida em 90% do tempo deve ser obedecida em implanta??es de sistemas celulares. Para que tal ?ndice seja obtido, considera??es e estudos envolvendo o ambiente espec?fico de atendimento s?o importantes. Este trabalho apresenta uma contribui??o nesse sentido

Orientador: Renato Baldini Filho / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-05T14:02:39Z (GMT). No. of bitstreams: 1 Oliveira_CarlosHenriqueRodriguesde_D.pdf: 6124095 bytes, checksum: d981e4a9e163dc0b358b20c451c92109 (MD5) Previous issue date: 2005 / Resumo: Este trabalho de tese estuda e analisa o desempenho dos sistemas móveis celulares GSM de segunda geração (2G), GPRS de segunda geração intermediária (2,5G) e CDMA2000 de terceira geração (3G). Na primeira parte deste trabalho de tese são avaliadas estratégias de compartilhamento dos canais de comunicação utilizados pelos sistemas GSM e GPRS, em busca daquela que resulte no menor impacto na qualidade dos serviços prestados por ambas as redes. Para esta avaliação, e como contribuição deste trabalho de tese, são desenvolvidos algoritmos aplicados em um simulador de eventos discretos desenvolvido em linguagem de programação C/C++. Os resultados das simulações mostram que a reserva de canais exclusivos ao sistema GPRS apresenta degradação na qualidade de serviço prestado pelo sistema GSM e que a melhor estratégia de compartilhamento é utilizar os canais de comunicação para o sistema GPRS nos momentos em que estes canais não são usados pelo sistema GSM. Na segunda parte deste trabalho de tese são feitas análises de desempenho dos sistemas móveis celulares de terceira geração, CDMA2000 lxRTT e CDMA2000 lxEVDO, baseadas na qualidade do serviço prestado por estas redes operando com várias aplicações simultâneas fim-a-fim entre cliente e servidor. Técnicas de detecção multiusuário e de antenas adaptativas são utilizadas na recepção destas aplicações e é avaliada a nova qualidade de serviço. Para estas análises de desempenho e como contribuição deste trabalho de tese, modelos de simulação são desenvolvidos utilizando a ferramenta OPNET. As redes CDMA2000 lxRTT e lxEVDO apresentam bom desempenho, analisado pelo parâmetro atraso da qualidade de serviço, na passagem de tráfego das aplicações HTTP, E-mail, VoIP, FTP, Telnet e Acesso a Banco de Dados. O desempenho da rede CDMA2000 lxEVDO melhora tanto com detecção multiusuário como com antenas adaptativas em relação ao receptor rake / Abstract: This thesis work studies and analyzes the performance of cellular mobile systems GSM of second generation (2G), GPRS of second intermediate generation (2,5G) and CDMA2000 of third generation (3G). In the first part of this thesis work, sharing strategies of communication channels used by GSM and GPRS systems are evaluated to find the one that results in the lowest impact in the quality of services supported by both networks. To this evaluation, and as contribution of this thesis work, algorithms applied in a discrete-event simulator developed in C/C++ programming language are developed. The simulation results show that the reserve of exclusive channels to the GPRS system presents degradation in the quality of service given for GSM system and that the better sharing strategy is to use the communication channels for the GPRS system whenever these channels are not used by the GSM system. In the second part of this thesis work, performance analyses of the third generation cellular mobile systems, CDMA2000 lxRTT and CDMA2000 lxEVDO, based on the quality of service supported by these networks operating with several end-to-end simultaneous applications between client and server are made. Multiuser detection and adaptive antennas techniques are used in the reception of these applications and the new quality of service is evaluated. For these performance analyses, and as contribution of this thesis work, simulation models are developed using the OPNET tool. The CDMA2000 lxRTT and lxEVDO networks present good performance analyzed through the delay parameter of quality of service running HTTP, E-mail, VolP, FTP, Telnet and Data Base Access applications. The CDMA2000 lxEVDO network performance improves using either multiuser detection or adaptive antennas when compared with rake receiver / Doutorado / Telecomunicações e Telemática / Doutor em Engenharia Elétrica

Submitted by Estagiário SPT BMHS (spt@fgv.br) on 2013-08-08T14:21:01Z No. of bitstreams: 1 Dissertação Eduardo Ferreira dos Reis.pdf: 829547 bytes, checksum: c2739a6a6f01d870ad0929a337f80f5a (MD5) / Approved for entry into archive by Estagiário SPT BMHS (spt@fgv.br) on 2013-08-08T14:21:15Z (GMT) No. of bitstreams: 1 Dissertação Eduardo Ferreira dos Reis.pdf: 829547 bytes, checksum: c2739a6a6f01d870ad0929a337f80f5a (MD5) / Approved for entry into archive by Estagiário SPT BMHS (spt@fgv.br) on 2013-08-08T14:21:32Z (GMT) No. of bitstreams: 1 Dissertação Eduardo Ferreira dos Reis.pdf: 829547 bytes, checksum: c2739a6a6f01d870ad0929a337f80f5a (MD5) / Made available in DSpace on 2013-08-08T14:21:45Z (GMT). No. of bitstreams: 1 Dissertação Eduardo Ferreira dos Reis.pdf: 829547 bytes, checksum: c2739a6a6f01d870ad0929a337f80f5a (MD5) Previous issue date: 2004-12 / O presente trabalho tem o propósito de analisar o processo de fidelização do consumidor corporativo no mercado de comunicação móvel celular. Serão investigadas as práticas comerciais da operadora de telefonia móvel celular Vivo, sob a ótica das teorias propostas. Para que esta análise ocorra será realizada uma pesquisa quantitativa com 120 empresas, divididas entre clientes e ex-clientes, entrevistas em profundidade com 08 empresas, também dividas entre clientes e ex-clientes e entrevistas em profundidade com os executivos responsáveis pela arquitetura das estratégias comerciais. Baseado no resultado da pesquisa, das entrevistas e da análise das teorias propostas, este estudo pretende apontar as práticas de marketing que podem gerar lealdade nos clientes empresariais de pequeno e médio porte no mercado de telefonia móvel celular. / The present work has the purpose of analyzing the process of the corporate consumer's loyalty in the market of cellular mobile communication. The commercial practices of the Vivo operator of cellular mobile telephony will be investigated, under the optics of the proposed theories. So that this analysis happens a quantitative research will be accomplished with 120 companies, divided between customers and former-customers, interviews in depth with 08 companies, also divide between customers and former-customers and interviews in depth with the responsible executives for the architecture of the commercial strategies. Based on the result of the research, of the interviews and of the analysis of the proposed theories, this study intends the marketing practices that can generate loyalty in the business customers of small and medium load in the market of cellular mobile telephony to appear.

The subject of the thesis is to examine what communication tools the students of Kungsmadskolan in Växjö uses to communicate on the Internet and what are the motives that lie behind this choice and continued use. The thesis focus on five groups of communication tools: chat, Internet forum, community, Internet telephony and e-mail. The purpose of the study is to investigate and understand the motive that lies behind the choice of Internet-based communication tools done by high school students. We have chosen a qualitative method to conduct our research. We have collected empirical data through discussions with two focus groups divided into one with only boys and one with only girls from Kungsmadskolan in Växjö. We then analyze this data and draw conclusions from it. Prior to the focus group discussions, we created a theoretical framework. This framework has been used to steer and support the discussions and as a theoretical support in our analysis. The framework consists of five parts: communication, communication tools, motivation, choice and acceptance. Through this study we have been able to establish that the most important influence on the students choice of communication tools comes from their friends. This means that the strongest motivation to their choice comes from the search for social communion. Communication tools that the students use are: MSN, Flashback.com, Forumet.nu, Fuska.nu, Bilddagboken.se, Lunarstorm, Community.se, Helgon.nu, Facebook, Hotmail, school-mail, work-mail and Spraymail. / Ämnet för uppsatsen är att undersöka vilka kommunikationsverktyg gymnasieelever på Kungsmadskolan i Växjö använder sig av för att kommunicera på Internet, vilka motiv som ligger bakom valet av kommunikationsverktyg och det fortsatta användandet. Uppsatsen inriktar sig på fem olika typer av kommunikationsverktyg: chatt, Internetforum, community, Internettelefoni och e-post. Undersökningens syfte är föreståelseinriktat, vilket innebär att vi ämnar att undersöka och förstå vilka motiv som avgör gymnasieelevernas val. Vi har valt en kvalitativ metod för vår undersökning. Vi har genom diskussion med två stycken fokusgrupper indelade i en med bara killar och en med bara tjejer från Kungsmadskolan i Växjö samlat in empirisk data. Denna data har vi sedan analyserat och dragit slutsatser utifrån. Inför våra diskussioner med fokusgrupperna har vi skapt en teoretisk referensram. Denna referensram har fungerat både som underlag för att styra och stödja diskussionerna och som teoretiskt stöd vid analysen av resultatet. Referensramen är uppdelad i fem avsnitt: kommunikation, kommunikationsverktyg, motivation, val och acceptans. Vi kom fram till att vänner i den direkta omgivningen har störst påverkan på vilken/vilka kommunikationsverktyg gymnasieeleverna använder sig av och väljer att börja använda. Detta innebär också att den starkaste motivationsfaktorn i valet är sökandet efter social gemenskap. Kommunikationsverktygen gymnasieeleverna använder är: MSN, Flashback.info, Forumet.nu, Fuska.nu, Bilddagboken.se, Lunarstorm, Community.se, Helgon.nu, Facebook, Hotmail, skolmail, jobbmail och Spraymail.

En este trabajo se ha diseñado una red de comunicaciones móvil 5G escalable que permita la recepción de imágenes provenientes de drones desplegados remotamente a lo largo del distrito de San Borja todo esto en concordancia con las normativas y estándares vigentes de la 3GPP, la cual está orientada a optimizar las herramientas de video vigilancia de la Municipalidad de San Borja, proponiendo una solución mediante dispositivos que permitan detectar actos delictivos mediante una plataforma de comunicación móvil de alta velocidad la cual hará uso de la infraestructura de red que ya se encuentra desplegada en el distrito. / In this work, a scalable 5G mobile communications network has been designed that allows the reception of images from drones deployed remotely throughout the San Borja district, all of this in accordance with the current regulations and standards of the 3GPP, which is oriented to optimize the video surveillance tools of the Municipality of San Borja, proposing a solution through devices that allow detecting criminal acts through a high-speed mobile communication platform which will make use of the network infrastructure that is already deployed in the district. / Tesis

Radio access technologies evolving fast, mobile operators have to handle an increasing amount of base stations and frequency bands for their network to continue to function. This is a costly venture for mobile network operators that continuously have to keep up to date with never-ending advancements in technologies, as base stations are costly to build and to maintain. It is therefore necessary for these companies to investigate when to close down base stations that are not necessary anymore. With the upcoming release of 5G, it is expected that 3G is going to be less and less used—as of 2018, it is already less used than 4G in developed countries.This thesis analyses the corporate data of a mobile operator, Telenor Sweden, in order to make clear which metrics are important to take into account as regards to deciding whether or not to close down a base station. It provides methods and models to help a mobile operator to take such a decision. It focuses on UMTS (3G) base stations, even though the results can be generalized for other technologies as well.It evaluates the economic feasibility of closing a base station, with regards to how many users are still connecting to it. More importantly, it explains for what reasons users’ devices switch to 3G, and investigates what can be done to avoid switching from 4G to 3G, so as to make it easier to close down a 3G site. It provides eventually a model to help to know when closing a site, given the traffic data of the operator. / Radioåtkomstteknologier utvecklas snabbt, mobiloperatörer måste hantera en ökande mängd basstationer och frekvensband för att deras nätverk fortsätter att fungera. Detta är ett dyrt satsning för mobilnätoperatörer som kontinuerligt måste hålla sig uppdaterade med oändliga tekniska framsteg, eftersom basstationerna är kostsamma att bygga och underhålla. Det är därför nödvändigt för dessa företag att undersöka när man ska stänga basstationer som inte längre är nödvändiga. Med den kommande utgåvan av 5G förväntas 3G att bli mindre och mindre används. Från och med 2018 används den redan mindre än 4G i industriländer. Denna avhandling analyserar företagsdata från en mobiloperatör, Telenor, för att klargöra vilka mätvärden som är viktiga att ta hänsyn till när det gäller att avgöra om en basstation ska stängas eller inte. Det ger metoder och modeller för att hjälpa en mobiloperatör att fatta ett sådant beslut. Den fokuserar på UMTS (3G) basstationer, även om resultaten kan generaliseras för annan teknik också. Det utvärderar den ekonomiska möjligheten att stänga en basstation, med tanke på hur många användare som fortfarande ansluter till den. Viktigare är det att det förklaras av vilka anledningar användarens enheter växlar till 3G och undersöker vad som kan göras för att undvika att växla från 4G till 3G, så att det blir lättare att stänga en 3G-basstation. Det ger så småningom en modell som hjälper till att veta när man stänger en webbplats, med tanke på operatörens trafikdata.

Kommunikationsvägar i business-to-business-kommunikation (B2B-kommunikation), så som e-post och telefoni, är idag utsatta för ett ökande hot från cyberattacker. Tidigare forskning har visat att många vanliga kommunikationsvägar är sårbara för hot, inklusive social manipulation och ransomware.  Studien undersökte hur IT-leverantörer arbetar för att säkerställa att deras B2Bkommunikationsvägar är säkrade, vilka sårbarheter de ser i sin befintliga miljö och vilka metoder de använder för att förhindra attacker. För att besvara frågorna genomfördes en kvalitativ fallstudie med en IT-leverantör. Semi-strukturerade intervjuer genomfördes för att ta reda på respondenternas åsikter och erfarenheter i relation till kommunikationsvägarna. Totalt 19 frågor inom olika kategorier ställdes till respondenterna.  Resultaten och analysen av intervjuerna indikerar att e-post och telefoni är de primära kommunikationssätten hos den IT-leverantör som deltog i fallstudien. Det skiljer sig också åt hur olika avdelningar föredrar att kommunicera. Resultaten visar även en oro över den växande hotbilden inom IT-sektorn. Som en följd är respondenterna medvetna om relevanta cyberattacker, så som ransomware eller andra attacker som involverar social manipulation. Respondenterna delar också hur de arbetar för att skydda sina kommunikationsvägar, samt identifierar områden för förbättring i en nära framtid. Slutligen kräver lagar och regler att IT-leverantören förbättrar och stärker sin IT-säkerhet, med framträdande exempel som GDPR och NIS-2-direktiven. / Communication paths in business-to-business communication (B2B-communication), such as email and telephony, are today exposed by an increasing threat of cyber attacks. Previous research has demonstrated that many common communication paths are vulnerable to threats, including social engineering and ransomware.  The study examined how IT-suppliers work to ensure that their B2B-communication paths are secured, what vulnerabilities in their existing environment do they see and what mitigation techniques they are using to prevent attacks. To answer the questions a qualitative case study was conducted with an IT-supplier. Semi-structured interviews were conducted to find out the respondents’ opinions and experiences in relation to the communication paths. A total of 19 questions across various categories were posed to the respondents.  The results and analysis of the interviews indicate that email and telephony are the primary modes of communication at the IT-supplier involved in the case study. It also differs in how different departments prefer to communicate. The results also indicate a concern about the growing threat landscape in the IT sector. As a result, the respondents are aware of relevant cyber attacks, such as ransomware or other attacks involving social engineering. The respondents also share how they work to protect their communication paths, as well as identify areas for improvement in the near future. Finally, laws and regulations requiere the IT-supplier to enhance and improve their IT-security, with prominent examples being GDPR and the NIS-2 directives.

Made available in DSpace on 2015-04-11T14:02:54Z (GMT). No. of bitstreams: 1 Mauro Ricardo da Silva Teofilo.pdf: 1416910 bytes, checksum: d4f41b9f784e48975a66441e08b837f1 (MD5) Previous issue date: 2007-09-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / With the intense use of applicative in mobile device, the question usability begins to invigorate strongly as a study object, it is being considered a determinant factor of the success of this segment of the mobile computation. This work proposes an improvement way in the usability of the embedded applicative in mobile devices, considering a new method of user interaction. The Mandos interaction method is based on task idea, which consists in a possible operation that could be executed in an applicative by the user and probabilities between task changes. The cited probabilities will be used for construction of the user interface to interact dynamically with the user. To validate the considered method was developed a framework, called Mandos, which propitiates functionalities to the applicative developer that uses Java technology. A case study will be presented where some prototypes of embedded applicative mobile was developed, using Mandos framework for the interaction method evaluation. The evaluation was established in order to identify any relation of usability gain or loss of applicatives, having like approvers the own users of the embedded applicative in mobile telephones. / Com o uso intenso de aplicativos em aparelho celulares a questão da usabilidade passa a vigorar fortemente como objeto de estudo, sendo considerado um fator determinante do sucesso deste segmento da computação móvel. Este trabalho propõe uma forma de aprimoramento da usabilidade dos aplicativos embarcados em aparelhos celulares, formulando um novo método de interação com o usuário. O método de interação Mandos foi baseado na idéia de tarefas, que consiste em uma operação de uma função de um aplicativo a ser executada pelo usuário, e nas probabilidades de transição entre tarefas. As probabilidades de transição entre tarefas serão utilizadas para construção da interface com o usuário, e tais probabilidades são alteradas no decorrer do uso do aplicativo, fazendo com que a interação seja dinâmica. Para validar o método proposto foi desenvolvido um framework, chamado de Mandos, que adiciona algumas funcionalidades já prontas para o desenvolvedor de aplicativos que utiliza a tecnologia Java. Será apresentado um estudo de caso onde alguns protótipos de aplicativos embarcados em telefone móveis foram desenvolvidos, usando o framework Mandos, para a avaliação do método de interação. A avaliação foi baseada de modo a identificar qualquer relação de ganho ou perda de usabilidade dos aplicativos, tendo com avaliador os próprios usuários dos aplicativos embarcados em telefones móveis.