Alexandre Santos

Alexandre Santos
University of Minho · Centro Algoritmi (CALG)

PhD with Habilitation

About

92
Publications
8,062
Reads
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510
Citations
Citations since 2017
27 Research Items
387 Citations
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Introduction
Alexandre J. T. Santos (IEEE SM-10) is Associate Professor with Habilitation in Informatics at the Informatics Department, Engineering School, University of Minho. In the R&D Centro ALGORITMI, e is now on the lead of the Computer Communications and Pervasive Media research group and also of the Computer Communicationds and Networks Laboratory. He has authored or co-authored numerous scientific papers at international refereed Journals and Conferences (with some best paper awards). Has been Project Evaluator for International and National R&D funding institutions and has served a TPC member for several IEEE, ACM and IFIP sponsored international conferences. He is IEEE Senior Member from IEEE Computer Society and member of IEEE Vehicular Technology Society and IEEE Communications Society.
Additional affiliations
September 2013 - present
R&D Centro ALGORITMI
Position
  • Managing Director
January 2008 - December 2010
University of Minho
Position
  • TriComFor - Tecnologias de Redes Inalambricas para Comunicacion y Formacion
October 2006 - September 2008
University of Minho
Position
  • CSI - Cooperation Serving Innovation

Publications

Publications (92)
Chapter
Previous studies have shown that the ITS solution called platooning allows the autonomous collaborative driving and can improve traffic safety and throughput. Traffic flow is optimized by Cooperative Adaptive Cruise Control (CACC), which allows for the automatic short-distance vehicle following, using inter-vehicle wireless communication in additio...
Conference Paper
Platooning is an emerging Intelligent Transportation Systems (ITS) application that can have a huge impact on road traffic. It allows vehicles to travel in a convoy manner, very close to each other with constant speeds and gaps. It uses Vehicular Ad hoc Networks (VANETs) as the underlying communication framework. These are a type of network with a...
Article
Full-text available
A Vehicular Adhoc Network (VANET) is a generic conceptualisation that can be applied to the communications domain of an Intelligent Transportation Systems (ITS). It defines requirements that allow the exchange of information between applications and services running on equipment that form a VANET, mainly moving vehicles, fixed road infrastructure's...
Article
Full-text available
Intelligent Transportation Systems (ITSs) are systems that aim to provide innovative services for road users in order to improve traffic efficiency, mobility and safety. This aspect of safety is of utmost importance for Vulnerable Road Users (VRUs), as these users are typically more exposed to dangerous situations, and their vehicles also possess p...
Article
Full-text available
Vehicular Ad hoc Networks (VANETs) are an emerging type of network that increasingly encompass a larger number of vehicles. They are the basic support for Intelligent Transportation Systems (ITS) and for establishing frameworks which enable communication among road entities and foster the development of new applications and services aimed at enhanc...
Article
Given the peculiarities of Mobile Computer Supported Collaborative Learning (MCSCL) environments, forming suitable groups in such learning environments represents a hard and time-consuming task. This is because many conditions related to mobile learners, devices, and environment should be considered. Unlike the existing solutions, the present paper...
Article
Given the peculiarities of mobile computer-supported collaborative learning (MCSCL) environments, forming suitable groups in such learning environments represents a hard and time-consuming task. This is because many conditions related to mobile learners, devices, and environment should be considered. Unlike the existing solutions, the present paper...
Article
Full-text available
It is expected in a near future that safety applications based on vehicle-to-everything communications will be a common reality in the traffic roads. This technology will contribute to improve the safety of vulnerable road users, for example, with the use of virtual traffic light systems (VTLS) in the intersections. This work implements and evaluat...
Chapter
A vehicle in a vehicular ad-hoc network (VANET) can perform wireless broadcasting by flooding to find a route to a node or to send an emergency warning, for example. However, this is usually a very demanding operation because it may originate broadcast storms, with high impact on redundancy and collision of packets, as well as channel bandwidth was...
Conference Paper
Web is a great resource and has become indispensable today. However, visually impaired users still face many difficulties in using the services available on the web. This paper presents experimental results of a semantic model that provides accessibility on websites for the visually impaired users. The model consists of components that do the page...
Conference Paper
Platooning is a solution that allows automated vehicles to travel very close to each other, enabling enhancements in terms of safety, traffic flow and highway capacities. Furthermore, it provides a more convenient and comfortable driving experience to the drivers. The research on Platooning covers a very large spectrum of areas, ranging from commun...
Article
Full-text available
A Vehicular Adhoc Network (VANET) is a generic communications conceptualization that can be applied to Intelligent Transportation Systems (ITS) and its main goal is to allow exchange of information between moving vehicles, fixed infrastructures, pedestrians with personal devices, and all other electronic devices able to connect to a VANET environme...
Conference Paper
VANETs (Vehicular Ad Hoc Networks) are networks of moving vehicles equipped with devices that allow spontaneous communication. Developing collaborative applications for VANETs has currently an increasing popularity in the Intelligent Transportation Systems (ITS) domain. This paper proposes a Platooning Management Protocol (PMP), whose implementatio...
Conference Paper
Web has becoming an invaluable source of knowledge. However, visu‐ ally impaired users have faced critical difficulties to access the services and data available on Web. To tackle this problem, this paper proposes a semantic model to improve accessibility to websites for users with visual disability. The model is made by components to identify and...
Article
As redes sociais em linha ocupam hoje um papel central na vida dos utilizadores da Internet. Os riscos inerentes à utilização destas ferramentas são diversos e agravam-se quando estamos perante utilizadores menores de idade. Sucede que as soluções apresentadas pelos vários agentes implicados não têm permitido que seja assegurada uma efectiva protec...
Article
Full-text available
Learners are becoming increasingly divers. They may have much personal, social, cultural, psychological, and cognitive diversity. Forming suitable learning groups represents, therefore, a hard and time-consuming task. In Mobile Computer Supported Collaborative Learning (MCSCL) environments, this task is more difficult. Instructors need to consider...
Article
Full-text available
The International Workshop on Future Internet and Smart Networks, FI&SN'2015, has been organized in conjunction by the Computer Communications and Networks Group, Centro ALGORITMI, University of Minho, Portugal and University of Haute Alsace, France.
Chapter
Recent advanced intelligent devices enable vehicles to retrieve information while they are traveling along a road. The store-carry-and-forward paradigm has a better performance than traditional communication due to the tolerance to intermittent connectivity in vehicular networks. Named Data Networking is an alternative to IP-based networks for data...
Conference Paper
This study presents the design and the development of a semantic model to transcode Internet websites, in order to improve accessibility for visually impaired people. Accessibility standards, semantic web concepts and site adaptation are the main points of this proposal. As a strategy of scope definition and model validation, this work analyses two...
Conference Paper
Full-text available
Students have different ways for learning and processing information. Some students prefer learning through seeing while others prefer learning through listening; some students prefer doing activities while other prefer reflecting. Some students reason logically, while others reason intuitively, etc. Identifying the learning style of each student,...
Conference Paper
Delay Tolerant Networks (DTN) were designed to allow delayed communications in mobile wireless scenarios where direct end-to-end connectivity is not possible. Nodes store and carry packets, deciding whether to forward them or not on each opportunistic contact they eventually establish in the near future. Recently, Named Data Networking (NDN) have e...
Conference Paper
Full-text available
Forming suitable learning groups is one of the factors that determine the efficiency of collaborative learning activities. However, only a few studies were carried out to address this problem in the mobile learning environments. In this paper, we propose a new approach for an automatic, customized, and dynamic group formation in Mobile Computer Sup...
Article
Internet of Things combined with Radio Frequency IDentification technology enable a whole new context for smart objects that are able to combine their physical and virtual existences. Radio Frequency IDentification, putting an identification label into every object, enables a smart system to get information, either real-time or virtual-linked infor...
Conference Paper
Currently, VANETs (Vehicular Ad-hoc Networks) are attracting a lot of interest in the scientific community and this is mainly due to its usefulness in the deployment of new Intelligent Transportation Systems. However, due to the very high mobility of vehicles in this sort of networks the handover process represents a serious problem, in particular...
Conference Paper
Due to its general usage in modern buildings, WiFi has been studied as a promising good low-cost solution to build localization services, but many other approaches are possible. Both industry and academy are putting considerable efforts in studying affordable and accurate alternatives, and no de facto standard exists yet. While technological divers...
Conference Paper
The increasing proliferation of mobile devices along with the evolution of access technologies has led to a growth on a variety of services which the end user has at his disposal. This technological development has resulted in a higher bandwidth availability at more competitive prices. Currently, the technological challenge involves integrating sev...
Chapter
The Portuguese National Research and Education Network (NREN) has a set of proprietary appliances for Quality of Service (QoS) monitoring probes within its backbone, very much dependant both on hardware and software details. Nowadays, several open source QoS monitoring systems and some Network Performance Measurement and Monitoring tools, developed...
Conference Paper
In the last years, the widespread of Cloud computing as the main paradigm to deliver a large plethora of virtualized services significantly increased the complexity of Datacenters management and raised new performance issues for the intra-Datacenter network. Providing heterogeneous services and satisfying users' experience is really challenging for...
Conference Paper
The use of Radio Frequency Identification technology (RFID) in medical context enables not only drug identification, but also a rapid and precise identification of patients, physicians, nurses or any other health caregiver. The combination of RFID tag identification with structured and secured Internet of Things (IoT) solutions enables ubiquitous a...
Article
The use of Radio Frequency IDentification technology (RFID) in the medical context enables drug identification but also a rapid and, of course, precise identification of patients, physicians, nurses or any other health caregiver. Combining RFID tag identification with structured and secure Internet of Things (IoT) solutions, one can establish a ubi...
Article
Full-text available
RFID technology (Radio Frequency IDentification) enables putting an identification label (e.g. tag) into a certain object and, by means of a reader, get the information related to it without any physical contact. The use of these tags in medical context enables a rapid and precise identification of each patient and, by means of Internet of Things (...
Conference Paper
Anycast is a new communication model, introduced by IPv6, relying in a communication paradigm of one to any. The primary characteristic of this model is tthe information directed to an anycast address is to be received by any node within a set of nodes that share the same address. Anycast communications emerged as a simple paradigm to support serve...
Article
Full-text available
This paper addresses the issue of mobility and QoS management principles as well as the mobility and QoS management integration in the sense of build a QoS-aware architecture for mobile Internet. After covering the mobility and QoS management principles and integration, this paper also proposes a new QoS-aware architecture for mobile Internet. This...
Article
Full-text available
This paper proposes a QoS micro-mobility solution capable of providing QoS support for global mobility. The solution comprises enhancements with regards to the mobility management of Mobile IPv6 (MIPv6) and in the resource management of the Differentiated Services (DiffServ) QoS model. The mobility management of MIPv6 was extended with fast and lo...
Conference Paper
Full-text available
Ideally, the future Internet must provide acceptable Quality of Service (QoS) to mobile users that are running real-time applications and are moving across different access points at high speeds. The user mobility presents a great challenge to the network layer in order to maintain users on going connections. Currently, the Internet protocol that m...
Article
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 a...
Article
Full-text available
As dificuldades dos alunos na aprendizagem das disciplinas de programação de computadores são frequentes, explicando o insucesso académico e o abandono de alguns alunos nos cursos de informática. Neste artigo, descrevemos tais dificuldades tomando o discurso de professores e de alunos, contrastando aqui alunos com bom e fraco rendimento Neste senti...
Conference Paper
Full-text available
Today, users want to have simultaneously mobility, Quality of Service (QoS) and be always connected to Internet. Therefore, this paper proposes a QoS micro-mobility solution able to provide QoS support for global mobility. The solution comprises enhancements in the mobility management of Mobile IPv6 (MIPv6) and in the resources management of Differ...
Conference Paper
Owner: alex, Added to JabRef: 2010.11.17
Conference Paper
Owner: alex, Added to JabRef: 2010.11.17
Conference Paper
Full-text available
In a nearby future wireless networks will run applications with special QoS requirements. FHMIP is an effective scheme to reduce Mobile IPv6 handover disruption but it does not deal with any other specific QoS requirement. Therefore new traffic management schemes are needed in order to provide QoS guarantees to real-time applications and this impli...
Conference Paper
Full-text available
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 application's QoS requirements. Therefo...
Article
DiffServ-like domains bring new challenges to quality of service (QoS) multicast routing simply by shifting the focus from individual flows into classes of flows. Packets are marked at edge routers and receive differentiated treatment according to the class and not the flow that they belong to. DiffServ therefore became adverse to multicast, as pac...
Conference Paper
Full-text available
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 tech...
Conference Paper
Full-text available
Most of current multicast QoS routing proposals are based on the principle that QoS routes must be computed for each request, where requests explicitly express their resource requirements. As a result, within this environment, the goal of QoS routing is to satisfy individual request requirements, resorting to resource reservation to maintain those...
Conference Paper
Full-text available
In networking research, the simulation is often the single way to overcome the lack of equipment needed for laboratory setup of complex experimental topologies, with diverse traffic pattern scenarios. Even for simpler topologies and traffic scenarios, the simulation remains attractive due to the available facilities on data collection, graphics gen...
Conference Paper
The NEMO (NEtwork MObility) protocol, as normalized by IETF, allows a transparent movement of a whole IPv6 network. This mobile network can thus attach to different points in the Internet without losing TCP/IP connectivity of its mobile nodes. In this paper we briefly describe the NEMO protocol and present a simple architecture deployed to test its...
Conference Paper
Este trabalho pretende avaliar a influência da selecção da versão do protocolo de transporte TCP no throughput conseguido pela ligação em ambientes de mobilidade. Os testes foram realizados no simulador Network Simulator 2 (NS2) em cenários de mobilidade. Os resultados obtidos permitiram escalonar as variantes do protocolo TCP em função do throughp...
Conference Paper
A Fundação para a Computação Científica Nacional e a Universidade do Minho, com o apoio do Instituto Politécnico de Portalegre, organizam a 8ª Conferência sobre Redes de Computadores - CRC’2005, com a finalidade de contribuir para a discussão de temas científicos e técnicos numa das áreas da informática de maior expansão e que maiores contributos t...
Conference Paper
Full-text available
Many already in use applications require the provision of QoS services from the underlying network infra-structure. This is particularly true for multicast, since it involves many participants at very sparse locations usually aiming to receive or send multimedia real-time streams. One way to provide QoS is through routing, since QoS aware multicast...
Conference Paper
A Fundação para a Computação Científica Nacional e a Universidade do Minho, com o apoio do Instituto Politécnico de Leiria, organizam a 7ª Conferência sobre Redes de Computadores - CRC’2004, com a finalidade de contribuir para a discussão de temas científicos e técnicos numa das áreas da informática de maior expansão e que maiores contributos tem t...
Conference Paper
We propose a lightweight traffic admission control scheme based on on-line monitoring which ensures multimedia services quality both intra-domain and end-to-end. The AC strategy is distributed, service-oriented and allows to control QoS and SLS without adding complexity to the network core. For each service class, AC decisions are driven by rate-ba...
Conference Paper
Full-text available
Future Internet applications are expected to have higher QoS requirements. Therefore, routing protocols must be adapted to find a path which satisfies such requirements. Most multicast applications are QoS sensitive in nature, because they involve the transmission of real-time multimedia data streams. There are several research projects aiming to e...
Conference Paper
Full-text available
While Differentiated Services reach maturity, and a few per hop aggregate behaviors are being standardized, little efforts are being carried out to enforce class differentiation by selecting alternative routes. Within a differentiated services multicast scenario, multiple multicast forwarding trees must be found, one per Class of Service (CoS), in...
Conference Paper
Achieving an admission control strategy for CoS networks covering both intra-domain and end-to-end operation is still an open issue. This paper discusses how AC can be carried out without adding significant complexity to the network control plane and proposes a distributed service-oriented AC model for these networks. The model only involves the ne...
Conference Paper
Full-text available
Traditional multicast routing protocols use RPF (Reverse Path Forwarding) concept to build multicast trees. This concept is based upon the idea that an actual delivery path to a node is the reverse of the path from this node to the source. This concept fits well in symmetric environments, but in a routing environment where Quality of Service is con...
Conference Paper
The advent of class-based networks has brought new needs for network traffic control in order to assure a certain QoS level. Despite the existing proposals, achieving a generic admission control (AC) strategy for traffic entering these networks is still an open issue. This paper provides new insights on how AC shall be accomplished proposing an enc...
Conference Paper
This paper studies and discusses the presence of LRD in network traffic after classifying flows into traffic aggregates. Following DiffServ architecture principles, generic QoS application requirements and the transport protocolin use, a classification criterion of Internet traffic is established. Using fractal theory, the resulting traffic classes...
Conference Paper
This document presents a new approach to Internet network management without changing the basic rules of the interface and encapsulation mechanisms of standard management transport protocols. The Internet network services management framework (INSMF) tries to overcome the most important limitations of the Internet network management framework (INMF...