Gean Davis Breda

Digital cities and open MANs: A new communications paradigm

Digital cities can be defined as a highly interactive digital communication environment built to mimic the behavior of real cities. Open access metropolitan area networks (Open MANs) are communication networks built to allow universal access of citys population to a single digital multimedia communication network. The goal of this paper is to discuss the impact in the community when delivering digital cities solutions upon the universal access scenario of the Open MANs. We also present results obtained of deployment of such solutions in some Brazilian cities and the perspectives for this project in Brazil in the coming years.

Construction of baselines for VoIP traffic management on open MANs

SUMMARY In the last century, owing to the constant evolution of technologies telecommunication networks have become increasingly robust, being able to support multiple services. These services are part of the heterogeneous network traffic that can be carried through the Internet. Many of these services, including VoIP, are latency sensitive. In other words, this means that their quality depends directly on the network quality of service. Since users tend to become more sensitive with the instability and unavailability of the network, it is important to improve traffic management. A particular type of data that could be used to improve VoIP traffic management is the Internet Protocol Detail Record (IPDR). IPDRs are tickets created by all VoIP call attempts which contain a group of information related to the call history. Because of its full range of information, IPDRs can be used to create VoIP traffic baselines. This paper presents the development of baselines based on IPDRs to support VoIP traffic management in open-access Metropolitan Area Networks (MAN). Copyright

QoS monitoring and failure detection

This paper deals with two algorithms for monitoring the QoS and based on it to detect failures in voice communication systems. These algorithms are based on the analysis of data stored in Call Detail Records (CDR). For each call one CDR or ticket is generated. These tickets contain data related to the call describing the system elements involved, such as time and duration of the call, phone types and numbers, SS7 signaling, trunks, time slots, what happen to the call, etc. The tickets are generated in PSTN switches or over VoIP gateways, for the case of Internet Protocol Detail Record (IPDRs). These tickets can be used to monitor the QoS and to detect faults focusing in different aspects related to the call, such as technical, economic, or social. Our main goal is to analyze and classify these algorithms according to their performance and use.

Modeling and simulation of ATM traffic management

This paper discusses modeling and simulation of ATM traffic management. It presents a survey on the requirements needed for such task considering previous work in the area. The survey encloses the following topics: the modeling approach; the requirements for trustworthy performance and QoS analysis; and the choice of the simulation environment where the models will be implemented. The paper also presents a new ATM network model implemented in a communication systems simulation environment called SimNT 2.0. The network model covers SVC routing and management, ATM traffic management functions, packet and cell transport/processing and client behavior. The TM functions taken into account include per-VC queuing, weighted fair-share scheduling, traffic shaping, effective bandwidth connection admission control, selective cell discarding, leaky-bucket traffic policing and traffic contract configuration and negotiation. Numerical results briefly demonstrate the network model.

LatinCon06 - Digital Cities and Open MANs: A New Communications Paradigm

Digital cities can be defined as a highly interactive digital communication environment built to mimic the behavior of real cities. Open access metropolitan area networks (Open MANs) are communication networks built to allow universal access of citys population to a single digital multimedia communication network. The goal of this paper is to discuss the impact in the community when delivering digital cities solutions upon the universal access scenario of the Open MANs. We also present results obtained of deployment of such solutions in some Brazilian cities and the perspectives for this project in Brazil in the coming years.

Knowledge Discovery: Data Mining by Self-organizing Maps

Due to the characteristics offered by automated management systems, municipal administrations are now attempting to store digital information instead of keeping their physical documents. One consequence of such fact is the generation of large volume of data. Usually, these data are collected by ICT technologies and then stored in transactional databases. In this environment, collected data might have complex internal relationships. This may be an issue to identify patterns and behaviors. Many institutions use data mining techniques for recognize hidden patterns and behaviors in their operational data. These patterns can assist to future activities planning and provide better management to financial resources. Intelligent analysis can be realized using the Support Tools and Support Decision Making (STSDM). These tools can analyze large volume of data through previously established rules. These rules are presented for STSDM in the training phase, and the tool learns about the patterns that should look. This paper proposes a model to support decision making based on self-organized maps. This model, applied to electronic government tools, can recognize patterns in large volume of data without the set of rules for training. To perform our case study, we use data provided by the city of Campinas, Sao Paulo.

Evaluation of quality in encrypted VoIP calls

The purpose of this work is to evaluate the quality of encrypted VoIP calls with different encryption algorithms through OpenVPN software, in order to identify differences in results between encryption algorithms and also differences between non-encrypted and encrypted calls. This evaluation will take into account the MOS (Mean Opinion Score), a method to indicate user satisfaction of voice communication quality. The encrypted VoIP calls will occur in different network scenarios that present different network bandwidths and different problems, like packet loss, out-of-order packets, and delay.

Multidimensional Evaluation based on Fuzzy Logic for e-Learning Environments

The ways of evaluating the performance of students have been exhaustively sought in the last decades. This paper understands the performance evaluation multidimensionality as a result of complex interactions. Therefore, it adopts an evaluation methodology based on fuzzy logic principles. The methodology steps make a guide for the development of a multidimensional evaluation capable of gauging the student learning in e-learning environments. For the development of the research, it was necessary to put the conditions into context of the theories, the models and systems utilized in the evaluation of students.