This Master’s Thesis in Electrical Engineering concerns the introduction of a Parlay gateway in Skanova’s public circuit switched telephone network, what network integrity problems this brings, and how to preserve the integrity of the network. There is a rising demand from the market on Skanova to be able to offer integrated and useful services via their network. Examples of such services are Web Controlled Call Forwarding and Virtual Call Centres. Until now, these services have been implemented with the Intelligent Network concept which is a technology for concentrating the service logic in the telephone network to centralised service platforms within the network operator’s domain. Developing new services in this environment is expensive and therefore, Skanova wants to open the network for third party service providers. The opening of the network is enabled by the introduction of a gateway implementing the open service interface Parlay. The crucial point when opening the network for third party service providers is to maintain the integrity of the network. Parlay is an object oriented Application Programming Interface that enables a third party service access to core network resources in a controlled manner. The authors’ definition of network integrity is: “the ability of a network to steadily remain in a safe state, while performing according to the expectations and specifications of its owner, i.e. delivering the expected functionality and providing means to charge for utilised network resources”. The thesis describes a few services implemented via the Parlay interface and points out examples of activities in these services that may jeopardise the integrity of the network. The described activities belong to one of the two categories: Call Control Functionality or Lack of Charging Instruments. The thesis also describes two important methods for addressing encountered integrity problems. The methods are: Parlay Service Level Agreement and Policy Management.</p> Finally, the solutions are compared and the conclusion is that Policy Management is a conformable and flexible method for addressing lots of integrity problems and that these are important qualities, since new integrity problems will arise all the time.

El presente trabajo consiste en el estudio de un conjunto de información comerciales de la compañía de telecomunicaciones Globalsat Perú y tiene la finalidad de identificar oportunidades de eficiencia en cuanto a los actuales planes de telefonía satelital. Los resultados del análisis permitirán a la compañía tener un sustento objetivo para la mejora del diseño de los productos que son parte del estudio. Esto a su vez, contribuirá con la mejora de la oferta comercial disponible en el mercado y, además, potencialmente tendrá un impacto en la rentabilidad de los planes analizados. En este estudio se utiliza como principal herramienta la metodología de ciencia de datos aprendida y sus fundamentos, poniendo en práctica de manera intensiva las técnicas de visualización desarrolladas a lo largo de los cursos pertenecientes a la especialización en ciencia de datos. / The following research consists in the analysis of a set of sales data from the telecom firm Globalsat Perú and has the main goal of identifying efficiency opportunities in the current satellite telephony plans. The results of this investigation will allow Globalsat to have objective proof for the improvement of the design of the products that are subject of this study. This will contribute with the development of the commercial offer available at the marketplace and will potentially have an impact in these plans’ profitability. This study uses as a main tool the data science methodology and its principles learnt, using intensively some of the visualization techniques worked during the courses of the data science specialization. / Trabajo de investigación

Les services de conversation Web en temps réel permettent aux utilisateurs d'avoir des appels audio et vidéo et de transférer directement des données sur Internet. Les opérateurs OTT (OTT) tels que Google, Skype et WhatsApp proposent des services de communication économiques avec des fonctionnalités de conversation évoluées. Avec l'introduction de la norme de Web Real Time Communication (WebRTC), n'importe quelle page Web peut désormais offrir des services d'appel. WebRTC est utilisé comme technologie sous-jacente pour déployer de nouvelles plateformes de communication centrées sur le Web. Ces plates-formes visent à offrir de nouvelles méthodes modernes de contact et de communication sur le web. Contrairement aux réseaux de télécommunication traditionnels, les identités sur le Web sont basées sur des profils d'utilisateur et des informations d'identification auto-affirmés. Par conséquent, les opérateurs Web sont incapables d'assurer la fiabilité de leurs abonnés. Les services de communication Web restent exposés à des menaces dans lesquelles le contexte social entre les parties communicantes est manipulé. Un attaquant se définit comme une entité de confiance pour transmettre de fausses informations à l'utilisateur ciblé. Les menaces typiques contre le contexte social comprennent la fausse représentation d'identité, l’hameçonnage, le spam et la distribution illégale de contenu. Afin d'assurer la sécurité sur les services de communication Web, la confiance entre les parties communicantes doit être établie. La première étape consiste à permettre aux utilisateurs d'identifier leurs participants communicants afin de savoir avec qui ils parlent. Cependant, l'authentification seule ne peut garantir la fiabilité d'un appelant. De nouvelles méthodes d'estimation de la réputation de l'appelant devraient également être intégrées dans les services d'appel Web. Par conséquent, dans cette thèse, nous présentons un nouveau cadre de confiance qui fournit des informations sur la fiabilité des appelants dans les réseaux de communication Web. Notre approche est organisée en quatre parties. Premièrement, nous décrivons la notion de confiance dans la communication web en temps réel. Un modèle de confiance est présenté pour identifier les relations de confiance nécessaires entre les entités d'un système de communication. Les paramètres requis pour calculer la confiance dans les services de communication Web sont officiellement introduits. Deuxièmement, nous montrons comment les protocoles Single-Sign-On (SSO) peuvent être utilisés pour authentifier les utilisateurs d'une manière Peer-to-Peer (P2P) sans dépendre de leur fournisseur de service. Nous présentons une comparaison entre trois protocoles d'authentification appropriés (OAuth, BrowserID, OpenID Connect). La comparaison montre que OpenID Connect est le meilleur candidat en termes de confidentialité des utilisateurs. Troisièmement, un modèle de calcul de confiance est proposé pour mesurer la fiabilité des appelants dans un réseau de communication. La légitimité et l'authenticité d'un appelant sont calculées à l'aide de recommandations, tandis que la popularité d'un appelant est estimée en utilisant son comportement de communication. Un abonné d'un service de communication sera capable de visualiser la confiance calculée d'autres membres avant d'initier ou d'accepter une demande d'appel. Enfin, la réputation d'un appelant est utilisée pour lutter contre les appels nuisibles générés sur les réseaux de communication. Les appels de nuisance sont décrits comme des appels de spam non sollicités en masse générés sur un réseau de communication à des fins de marketing et de tromperie. Les enregistrements de données d'appel et les commentaires reçus par les parties communicantes sont utilisés pour déterminer la réputation de l'appelant. La réputation évaluée est utilisée pour différencier les spammeurs et les appelants légitimes du réseau / Real-time web conversational services allow users to have audio and video calls over the Internet. Over-The-Top operators such as Google and Facebook offer cost-effective communication services with advanced conversational features. With the introduction of WebRTC standard, any website or web application can now have built-in communication capabilities. WebRTC technology is expected to boost Voice-Over-IP by making it more robust, flexible and accessible. Telco operators also intend to use the underlying technology to offer communication services to their subscribers over the web. Emerging web-centric communication platforms aims to offer modern methods of contacting and communicating over the web. However, web operators are unable to ensure the trustworthiness of their subscribers, since identities are based on self-asserted user profiles and credentials. Thus, they remain exposed to many social threats in which the context between communicating parties is manipulated. An attacker usually misrepresents himself to convey false information to the targeted victim. Typical social threats include phishing, spam, fraudulent telemarketing and unlawful content distribution. To ensure user security over communication networks, trust between communicating parties needs to be established. Communicating participants should be able to verify each other’s identity to be sure of whom they are talking to. However, authentication alone cannot guarantee the trustworthiness of a caller. New methods of estimating caller’s reputation should also be built in web calling services. In this thesis, we present a novel trust framework that provides information about the trustworthiness of callers in web communication networks. Our approach is organized in four parts. Firstly, we describe the notion of trust in real-time web communication services. A trust model approach is presented to formally introduce the trust computation parameters and relationships in a communication system. Secondly, we detail the mechanism of identity provisioning that allows communicating participants to verify each other’s identity in a Peer-to-Peer fashion. The choice of authentication protocol highly impacts user privacy. We showed how OpenID Connect used for Single-Sign-On authentication purposes can be effectively used for provisioning identities while preserving user privacy. Thirdly, a trust computational model is proposed to measure the trustworthiness of callers in a communication network. The legitimacy and genuineness of a caller’s identity is computed using recommendations from members of the network. On the other hand, the popularity of a caller is estimated by analyzing its behavior in the network. Each subscriber will be able to visualize the computed trust of other members before initiating or accepting a call request. Lastly, the reputation of a caller is used to combat nuisance calls generated over communication networks. Nuisance calls are described as unsolicited bulk spam phone calls generated for marketing and deceptive purposes. Caller’s reputation is computed using the diversity of outgoing calls, call duration, recommendations from called participants, reciprocity and repetitive nature of calls. The reputation is used to differentiate between legitimate and nuisance calls generated over the network

La alta demanda de servicios móviles, el aumento de operadoras en el mercado y su baja calidad de servicio, les ha dado motivos a los usuarios para migrar a otras operadoras al no estar conformes con el servicio brindado,no obstante no todos lo hacen. Por medio de una investigación cuantitativa a una muestra de 400 usuarios de servicios móviles, se estudiará el impacto del Service quality, customer satisfaction en el customer loyalty en la categoría de telefonía móvil en el Perú, colocando al switching cost como una variable moderadora. La falta de estudios sobre la industria de celulares en el Perú tomando el switching cost como variable moderadora es el principal motivo de esta investigación. / The high demand for mobile services, the increase in operators in the market and their low quality of service, have given users reasons to be able to migrate to other operators by not being satisfied with the one they present, however, not all do it. Through a quantitative study, the impact of Service quality, customer satisfaction on customer loyalty in the mobile telephony category in Peru is investigated, placing switching cost as a moderating variable. The lack of studies on the cell phone industry in Peru taking the switching cost as a moderating variable is the main reason for this research. / Trabajo de investigación

Video conferencing has been a part of many communication platforms over the years. Over the last decades users have moved from dedicated telephony networks to the Internet, and recently to the Web. With the introduction of Web Real-Time Communication (WebRTC) it is now possible to make voice- and video calls simply by visiting a web page, without having to install any additional software. Services that enable multi-user conferences are quite common. However existing solutions such as the Multipoint Control Unit (MCU) inherently do not scale and can be a single point of failure, due to its centralized architecture. This can lead to high maintenance costs and poor service availability.To solve the scalability- and availability problems of video-conferencing services, a decentralized alternative to the MCU is proposed. A decentralized conferencing system uses the distributed resources of its users instead of relying on a central server. This means that the system can handle an increasing number of users without having to upgrade any server infrastructure. Additionally, failures are only partial and can happen regularly without affecting the rest of the system. This report presents the development of a protocol built on top of WebRTC that enables completely decentralized multi-user conferencing. It includes a distributed algorithm for voice-activated switching to reduce the computation and network resources used. A load-balancing technique based on media stream relays is used to distribute the resource requirements of the conference participants. The protocol is implemented as a Javascript library that can be included in a web application. A proof-of-concept web application is developed using the library and its performance is evaluated. The performance data is analyzed and the results are used to make incremental improvements to the protocol and implementation. Although not all features of the protocol are implemented, the tests show promising results. The application allows multiple users to participate in high-definition video conferences, with no server infrastructure aside from a Mini PC that hosts a web server and a WebRTC signaling server. / Videokonferenser har varit en del av många olika kommunikationsplattformar genom åren. Tekniken har yttats från dedikerade telefonnnät,, till Internet, och på senare tid till webben. I och med introduktionen av WebRTC (Web Real-Time Communication) är deti dag möjligt att enkelt deltaga i röst- och videosamtal genom att gå till en webbsida utan att behöva installera någon programvara annat an en webbläsare. De flesta existerande konferenstjänster är byggda med en centraliserad arkitektur, vilket kan leda till tekniska problem när antalet användare ökar eller när fel uppstår i systemens centrala servrar. Dessa problem kan leda till driftstopp och skada tjänstens tillgänglighet för användarna. Den här rapporten täcker utvecklingen av ett protokoll som tillsammans med WebRTC kan användas för att bygga en helt decentraliserad konferenstjänst. Målet är att tjänsten ska vara oberoende av centrala servrar, och på så vis lösa problemen med skalbarhet och tillgänglighet. Protokollet implementeras i en webbapplikation som testas och utvärderasöver flera iterationer för att hitta nya förbättringar. Testerna visar lovande resultat. Slutsatsen dras det är fullt möjligt att bygga en konferenstjänst på detta sätt, och möjligheter för framtida optimeringar och testfall föreslås.

[ES] Esta investigación se ha centrado en la identificación de qué servicios pueden ser considerados como determinantes como competitivas, en las relaciones prepago con sus clientes, por parte de las principales operadoras de telefonía móvil en España, y si la existencia de mayores niveles de confianza, compromiso y lealtad por parte de los empleados de las operadoras, con cada vez mayor presencia en redes sociales, pueden alterar su posición. A través de varios estudios, siguiendo la metodología de Concept Mapping con análisis clúster, al objeto de obtener la información necesaria fundamentalmente de tipo cualitativo, se puede obtener e identificar aquellos niveles de afectación en las relaciones empleados-subordinado con repercusiones en la competitividad de las operadoras de telefonía móvil en España. En un primer estudio analizo los motivos de lealtad de los clientes con la operadora, identificando las principales dimensiones y a continuación, en un segundo estudio identifico las principales razones de desconexión de anteriores operadoras, identificando sus dimensiones con las variables anteriormente descritas. / [CA] Aquesta investigació s'ha centrat en la identificació de quins serveis poden ser considerats com a determinants com a competitives, en les relacions prepagament amb els seus clients, per part de les principals operadores de telefonia mòbil a Espanya, i si l'existència de majors nivells de confiança, compromís i lleialtat per part dels empleats de les operadores, amb cada vegada major presència en xarxes socials, poden alterar la seua posició. A través de diversos estudis, seguint la metodologia de Concept Mapping amb anàlisi clúster, a fi d'obtindre la informació necessària fonamentalment de tipus qualitatiu, es pot obtindre i identificar aquells nivells d'afectació en les relacions emprats-subordinat amb repercussions en la competitivitat de les operadores de telefonia mòbil a Espanya. En un primer estudi analitze els motius de lleialtat dels clients amb l'operadora, identificant les principals dimensions i a continuació, en un segon estudi identifique les principals raons de desconnexió d'anteriors operadores, identificant les seues dimensions amb les variables anteriorment descrites. / [EN] This research has focused on the identification of which services can be considered as competitive determinants on prepaid contracts with customers, by the main mobile phone companies in Spain, and whether the existence of higher levels of trust, commitment and loyalty on the part of the employees, with increasing presence in social networks, can alter their position. Through several studies, following the Concept Mapping methodology with cluster analysis in order to obtain the necessary information, primarily of a qualitative type, the levels of affectation in employee-subordinate relationships with repercussions on the competitiveness of the mobile phone companies in Spain can be identified. In a first study, I analyze the reasons for customer¿s loyalty with the company, identifying the main dimensions and then in a second study I identify the main reasons of why customers leave their previous mobile operators, identifying dimensions with the variables described above. / Gil Conesa, I. (2022). Influencia de la confianza directiva y el compromiso de los empleados como determinantes de la lealtad y fidelización del cliente a través de las redes sociales en las relaciones contractuales prepago en operadoras de Telefonía Móvil [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/182949

This PhD thesis in Spatial Planning argues for the importance of understanding the approaches to knowledge and rationalities embedded in spatially relevant decision-making. It emphasises the significance of seeing law as an empirical object of study for planning and environmental management. The Swedish development of wind power and 3G mobile infrastructures are used as cases to study these issues of principal interest. It is a compilation thesis consisting of a comprehensive introductory framework and five articles or chapters that have also been published elsewhere. The study is based on three main perspectives: Level of decision-making, legitimacy of different forms of knowledge involved in the process, and the sociolegal tension between formal law and its practical consequences. The thesis deals with problems stemming from the multi-level tensions in the planning and implementation that exist between the national, the regional and the local authorities. The legal context is analysed from the sociolegal perspective, in particular how the juridification of siting and permit conflicts determines what type of knowledge that can legitimately affect the decision-making and thereby set conditions for public participation. Finally, the thesis elaborates on the largely counterproductive results of the strong emphasis on “efficiency” in the revision of planning and permit processes for wind power and 3G-infrastructure, and what can be learnt from the experiences of the attempts at increasing efficiency. A combination of methods has been employed in the studies, and the data comes from a range of sources such as a large set of mast building permits, a sample of wind permit cases, as well as appealed permit cases. In addition, interviews have been conducted with judges from relevant courts, including regional handling officers who assess wind turbine applications. Legal documents such as preparatory work and licence conditions have also been analysed. The results show that there is a legal-rhetorical adaptation to the expert-based decision-making in court when permits are appealed. Further, the administrative levels interact poorly in the overall implementation. The national decisions, irrespective of the normative viewpoint of who should control the landscape planning, could be better informed of the preconditions at a local level that factually define the outcome of the implementation. The author, Stefan Larsson, holds a PhD in Sociology of Law, an LLM and is a sociolegal researcher who generally studies issues in the intersection of conceptual, sociolegal and technological change. The thesis has been supervised by Professor Lars Emmelin, The Swedish School of Planning, BTH, and co-supervised by Professor Karsten Åström, the Department of Sociology of Law, Lund University. The thesis is the result of research within the programme Tools for environmental assessment in strategic decision-making, MiSt, funded by The Swedish Environmental Protection Agency and the Centre for Work, Technology and Social Change at Lund University. / <p>Full text available: http://lup.lub.lu.se/luur/download?func=downloadFile&amp;recordOId=4587806&amp;fileOId=4 588973</p>

Next generation wireless systems have an IP-based infrastructure with the support of heterogeneous access technologies. One research challenge for next generation all-IP based wireless systems is to design intelligent mobility management techniques that take advantage of IP-based technologies to achieve global roaming between various access networks. To support global roaming, next generation wireless systems require the integration and interoperation of heterogeneous mobility management techniques. Mobility in a hierarchical structure or multilayered environment should be supported. The objective of this study is to develop new mobility management techniques for global roaming support in next generation all-IP based wireless systems. More specifically, new schemes for location management and paging in Mobile IP for network layer mobility support, and new schemes for location management and handoff management in heterogeneous overlay networks for link layer mobility support are proposed and evaluated. For network layer mobility support, a distributed and dynamic regional location management mechanism for Mobile IP is proposed. Under the proposed scheme, the signaling burden is evenly distributed and the regional network boundary is dynamically adjusted according to the up-to-date mobility and traffic load for each terminal. Next, a user independent paging scheme based on last-known location and mobility rate information for Mobile IP is proposed. The proposed scheme takes the aggregated behavior of all mobile users as the basis for paging. For link layer mobility support, an IP-based system architecture for the integration of heterogeneous mobility management techniques is proposed. Three location management schemes under this IP-based architecture are proposed. All the three schemes support user preference call delivery which is a very important feature of next generation wireless communications. A threshold-based enhancement method is also proposed to further improve the system performance. Finally, a hybrid resource allocation scheme for handoff management in wireless overlay networks is proposed. Under this scheme, the overall system resources can be optimally allocated when mobile users are covered by multiple overlay networks.

Family conversation between homes is difficult to initiate at mutually agreeable times as neither participant has exact knowledge of the other's activities or intentions. Whether calling to plan an important family gathering or simply to connect with family members, the question is: Is now a good time to call? People expect friends and family to learn their activity patterns and to minimize interruptions when calling. Can technology provide awareness cues to the caller, even prior to the initiation of the call? This research focuses on sampling the everyday activities of home life to determine environmental factors, which may serve as an indicator for availability. These external factors may be effective for identifying household routines of availability and useful in determining when to initiate conversation across homes. Several workplace studies have shown a person's interruptibility can be reliably assessed and modeled from specific environmental cues; this work looks for similar predictive power in the home. Copresence, location, and activity in the home were investigated as correlates to availability and for their effectiveness within the social protocol of family conversation. These studies indicate there are activities that can be sensed, either in real-time or over some time span, that correlate to self-reported availability. However, the type and amount of information shared is dependent upon individual preferences, social accessibility, and patterns of activities. This research shows friends and family can improve their predictions of when to call if provided additional context, and suggests that abstract representations of either routines or explicit availability status is sufficient and may be preferred by providers. Availability prediction is feasible in the home and useful to those outside the home, but the level of detail to provide in particular situations needs further study. This work has implications for the development of groupware systems, the automatic sensing of activity to deal with interruption, and activity recognition in the home.

<p>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.</p> / <p>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.</p>