Portugal Telecom

About: Portugal Telecom is a company organization based out in Lisbon, Portugal. It is known for research contribution in the topics: Quality of service & WiMAX. The organization has 144 authors who have published 230 publications receiving 2686 citations.

Methodologies of support to the execution of Risk Management

Abstract: Since Risk Management became an organizational concern lots of guidelines have been published. On the last quarter of 2009 it was published a new one that proposes itself to be a real standard for the risk management, the ISO 31000. However, any of the guidelines included in the scope of this work covers the implementation and afterwards the execution of themselves, even the ISO 31000. So, this reality joined with the heterogeneity of the companies turns the implementation and execution of such guidelines much difficult. In this work we propose a methodology to support the implementation and execution of risk management, having as test bed the risk management process of ISO 31000. The work is focused mainly in the activities Establishing the Context and Risk Assessment, which are the ones that present the greatest challenges of implementation and execution. The methodology is based in two basic components: entrepreneurial cartography and multidimensional techniques of analysis (ROLAP). Its validation was done in a real organizational context, submitting it at the treatment of the technological risk, namely to the unavailability risk event.

Aneurisma da aurícula direita após traumatismo torácico: apresentação tardia

Abstract: Resumo Relata-se o caso de um paciente de 59 anos de idade, com historia de traumatismo toracico grave com fratura de varios arcos costais aos 20 anos, com inicio recente de cansaco e palpitacoes, a quem foi detetada taquicardia auricular, convertida farmacologicamente. Os estudos imagiologicos (ecocardiografia transtoracica e RMN) realizados inicialmente levantaram a hipotese de se tratar de cor triatriatum ou anomalia de Ebstein. Posteriormente, por recorrencia da arritmia, foi efetuada nova avaliacao ecocardiografica transtoracica que estabeleceu o diagnostico de aneurisma da auricula direita. A arritmia foi convertida eletricamente. Durante o seguimento de 18 meses o paciente encontra-se assintomatico, sem recorrencia de arritmias, medicado com carvedilol (apos periodo sob amiodarona) e varfarina .

A management system providing real distribution of management tasks with time and space independence

Abstract: Actual management systems do not fulfil a number of requirements identified as mandatory for an efficient and effective network management. The simple adoption of solutions like Java's RMI or OMG's CORBA, do not solve all problems and may originate others. This paper describes the architectural and functional model for the proposed management system, that satisfy a number of identified requirements. Special attention is devoted to the information model, proposing a new structure for it. Within the text some simple application examples of ATM networks are given. Finally, a brief analysis of two distinct ATM switches from different vendors is given referring to the possible added value that the proposed system can bring when managing those devices.

Quality Evaluation Methods to Improve Enterprise VoIP Communications

Abstract: In the last few years there has been a dramatic development in voice communications technology with a significant move towards Voice over the Internet Protocol (VoIP). Since the Internet was primarily designed as a besteffort technology, good quality conversation and intelligibility are not guaranteed. In this paper we address quality evaluation of voice communications in the context of modern enterprises using VoIP as an emerging technology with impact in their activity. Relevant factors for service providers and enterprises using VoIP technology are described, such as those related to measurement of intelligibility and evaluation of overall voice communications quality. Also, the most relevant voice quality evaluation methods recommended by the ITU-T are described along with the main features that can be used to improve voice communications. Fundamental concepts are presented, such as intrusive, non intrusive, objective, subjective and parametric methods. Mastering the concepts of such emerging technology, has recently lead to research and development of a model-based voice quality monitor for VoIP services. After its successful implementation, it is now fully operational in a Portuguese telecom operator.

Expedient reconfiguration in the cloud

Abstract: Cloud computing enables high-availability and secure access to information. Multihoming aware mechanisms in the cloud enable resilience support with enhanced access to services in the case of failures or high-load events. The Stream Control Transport Protocol (SCTP) natively supports multihoming with a primary-backup protection model. This paper introduces the Fast Reconfiguration Algorithm (FRA) that configures proactively SCTP, according to the state of the network and resources usage. Evaluation results, from tests performed in the cloud environment of a Telecom Operator, demonstrate that FRA adapts to different kinds of failures, network conditions and server load, improving significantly the performance of high volume data transfers.