Nuno Vasco Lopes

Efficiency of PRI and WRR DiffServ Scheduling Mechanisms for Real-Time Services on UMTS Environment

The next generation of mobile phones will be probably all-IP based enabling users to access Internet services. In order to make this possible a satisfactory quality of service, at least equal to the fixed Internet, must be ensured. To achieve this goal an end-to-end QoS system must be constructed. Another fact is the dominance of IP over other technologies due, in large measure, to its characteristic of working with heterogeneous technologies. Consequently, being IP the common denominator on a heterogeneous environment, it is important to develop end-to-end IP QoS guarantees for the different applications over distinct access technologies. This is particularly important for cellular wireless networks due to the ever growing expansion of mobile phone users. One way to contribute to this goal is to apply DiffServ QoS mechanisms to UMTS technology in order to model an End-to-End QoS communication system. A mapping of DiffServ CodePoints into UMTS classes can be applied in order to get efficient PHB configurations. This paper proposes an architecture to support end-to-end quality of service to several application services running on mobile UMTS user agents and communicating with servers located in a wired internet. The proposed architecture is based on a DiffServ model, where QoS parameters are set either by the user agent or by the SGSN. In particular, RED queue management and PRI or WRR scheduling policies are enforced. Different UMTS traffic classes are mapped into different DiffServ parameters. The performance of this architecture has been evaluated by simulation using NS, assuming different network load scenarios. In particular, the delay and packet loss experienced by VoIP, Video, FTP and HTTP traffic are evaluated in the cases of PRI and WRR scheduling policies, and compared to those measured when DiffServ is not implemented. Finally, a revenue function to estimate the profits that an ISP could expect by using a DiffServ implementation on IP UMTS core routers is proposed.

Implementing range queries with a decentralized balanced tree over distributed hash tables

Range queries, retrieving all keys within a given range, is an important add-on for Distributed Hash Tables (DHTs), as they rely only on exact key matching lookup. In this paper we support range queries through a balanced tree algorithm, Decentralized Balanced Tree, that runs over any DHT system. Our algorithm is based on the B+-tree design that efficiently stores clustered data while maintaining a balanced load on hosts. The internal structure of the balanced tree is suited for range queries operations over many data distributions since it easily handles clustered data without losing performance. We analyzed, and evaluated our algorithm under a simulated environment, to show its operation scalability for both insertions and queries. We will show that the system design imposes a fixed penalty over the DHT access cost, and thus inherits the scalability properties of the chosen underlying DHT.

Internet of things and cloud computing

With advances in communication technology, future internet presents numerous opportunities to develop new systems designed to make day to day life easier and to enhance and prolong the life of people with disabilities. This motivation propels the development of new services that integrate the mobility of cloud systems and the diversity of IoT (Internet of Things). It will enable us to create new and more independent care systems for people with disabilities, enabling a certain degree of independence. This can have a psychological and social impact due to the better quality of life that enables. Other motivation is the versatility and mobility of services it can provide, making those services available. In this paper is explored and explained the different kinds of technologies that can be integrated to enable creation of future internet platforms. Also, an IoT Cloud platform will be analyzed and some tests will be made, ending with some conclusions and lessons learned in this work.

QoS-aware architecture for FHMIP micromobility

Wireless networks will certainly run applications with strict QoS requirements and so, micro-mobility protocols such as fast hierarchical mobile IPv6 (FHMIP) are useful tools to accomplish this new feature. The FHMIP is an effective scheme to reduce Mobile IPv6 handover disruption, however it does not support applications QoS requirements. Therefore, in order to provide QoS guarantees for real-time applications it is necessary to develop new traffic management schemes; this implies the optimization of network mobility support and also some network congestion control. A traffic management scheme of this type should take into account the QoS requirements of handover users and should implement a resource management (RM) scheme in order to achieve this. In this paper, a new RM scheme for the DiffServ QoS model is proposed. This new scheme is implemented by access routers as an extension to FHMIP micromobility protocol. In order to prevent QoS degradation of the existing traffic, access routers should evaluate the impact of admitting a new mobile node (MN), previously to the handover. This evaluation and sequent decision on wether admitting or refusing MNs traffic is based on a measurement-based admission control (MBAC) algorithm. This architecture, that has been implemented and tested using ns-2, includes a simple signaling protocol, a traffic descriptor and exhibits an adaptive behavior to traffic QoS requirements. All the necessary measurements are aggregated by class-of-service, thus avoiding maintaining state on the individual flows.

Reference model and method of evaluation for smart cities in government portals: a study of the Portuguese and Brazilian reality

The urban issue is currently of great interest. The cities and its multiple socio-cultural and political manifestations have been acquiring, from the technological changes of Information Society, new in-struments for ensuring the quality of the future life of most of the world popula-tion, and this subject has been named in doctrine as Smart Cities. According to this, several organizations have been gathering efforts in order to monitoring the different dimensions of smart cities. It is thus of utmost importance to analyse the main (inter)national metrics and indicators for evaluating the levels of smartness of cities, with special focus in governance. For this, and based in bibliographic revi-sion and realização of conceptual proof, it is proposed an evaluation method that expresses the variables capable of enhanc-ing the intelligent governance in Govern-ment portals. From the research undertak-en, it may be verified that studies in this field are still incipient. On the other side, in spite of the knowledge of the limits of such approach, this method will serve as a new focus on the fiability of the commu-nication process between government and society and as source of consultation and evaluation of the intelligent governance. Finally, it is believed that tha periodical application of this method will allows, besides the monitoring and control of public policies, also the opening up of new ways of citizens participation.

A QoS-enabled resource management scheme for F-HMIPv6 micro mobility approach

In the near future, wireless networks will certainly run real-time applications with special Quality of Service (QoS) requirements. In this context micro mobility management schemes such as Fast Handovers over Hierarchical Mobile IPv6 (F-HMIPv6) will be a useful tool in reducing Mobile IPv6 (MIPv6) handover disruption and thereby to improve delay and losses. However, F-HMIPv6 alone does not support QoS requirements for real-time applications. Therefore, in order to accomplish this goal, a novel resource management scheme for the Differentiated Services (DiffServ) QoS model is proposed to be used as an add-on to F-HMIPv6. The new resource management scheme combines the F-HMIPv6 functionalities with the DiffServ QoS model and with network congestion control and dynamic reallocation mechanisms in order to accommodate different QoS traffic requirements. This new scheme based on a Measurement-Based Admission Control (MBAC) algorithm is effective, simple, scalable and avoids the well known traditional resource reservation issues such as state maintenance, signaling overhead and processing load. By means of the admission evaluation of new flows and handover flows, it is able to provide the desired QoS requirements for new flows while preserving the QoS of existing ones. The evaluated results show that all QoS metrics analyzed were significantly improved with the new architecture indicating that it is able to provide a highly predictive QoS support to F-HMIPv6.

Research Gaps on Public Service Delivery

This paper follows the research framework for context-specific public service delivery presented at ICEGOV 2016 [1]. The research has been conducted at the UNU-EGOV unit during the last year. The paper presents the research landscape for ICT enabled public service delivery scientific and policy literature. The findings are analyzed and presented in a conceptual framework allowing us to identify the core dimensions and sub-dimensions of public service delivery. The paper concludes by outlining the research gaps identified by the study and a series of policy recommendations to enhance public service delivery. The results showed that the Innovation and Evaluation dimensions and their sub-dimensions, Innovating Public Procurement, Collective Learning and Intelligent, Evidence-Based Policy Making and Social Media Impact are the areas with less investigation.

Empirical analysis of the current digital divides since 2010

As part of a larger study, this research paper answer two key research questions: How are we performing better in bridging the digital divide? What are the trends and most influential factors in digital divide? To answer these two questions, the paper uses ITU data for 209 countries between 2010 and 2015. The descriptive statistics show that the key reason for the persistent digital divide seen between regions, countries and socio-economic groups is a financial one! A deep dive correlation analysis finds direct causation between the variable tested, i.e. physical access to the internet (i.e. input factor) and use of internet and internet-based services (i.e. output factor). Mobile infrastructure is found to initially provide better value and faster roll-out of physical access to internet infrastructure, but may not be a long-term solution as the actual use of Internet-based services will lead to increased demand for high-quality bandwidth. The relative cost of internet access is a key challenge to bridge the digital divide between lower income and high-income countries. By comparison, there is only a limited digital divide between low- and high-income groups and rural and urban areas in high-income countries. Findings indicate that once roughly half of a population has physical access to the internet, actual use of Internet-based services reach a tipping point and will automatically increase, thus lending support to Technology Acceptance Models.

Behavioural Biometrics for Authentication and Stress Detection – A Case Study with Children

This article presents a stress detection model based on real time collection and analysis of physiological signals monitored by non-invasive and non-intrusive sensors. The assumption of a state of stress is made taking into account the validation of a certain number of biometric reactions to some specific situations. The biometric data collected is also used to create a method capable of guaranteeing user’s authentication. To validate this model, an experiment was set, demonstrating that it is possible to infer stressful situations by monitoring some specific physiological signals.

Knowledge Societies in China, Portugal, and Uganda

In September 2015, the United Nations (UN) Member States subscribed the Sustainable Development Goals (SDG) of the 2030 Agenda (General Assembly 2015). This work makes an analysis on how Knowledge Societies can effectively contribute for the achievements of the Agendas 17 Sustainable Development Goals. Moreover, it will be presented the research overview conducted by UNU-EGOV for producing the United Nations Educational, Scientific and Cultural Organization (UNESCO) Knowledge Societies Handbook (UNESCO/IFAP and UNU-EGOV 2016). In addition, three countries from three different Continents of Asia, Europe and Africa - China, Portugal and Uganda respectively - will be analyzed in the context of the knowledge societies architecture proposed in the handbook. For making that analysis a set of indicators collected from the “The World Bank” (The World Bank 2016) and “International Telecommunication Union” (ITU) (ITU 2015) databases have been selected. The indicators have been interpreted taking into consideration the socio-cultural, political, and economic context of each of the three countries.