Publication History

Jornals & Magazines

 
On the application of contextual IoT service discovery in Information Centric Networks. José Quevedo, Mário Antunes, Daniel Corujo, Diogo Gomes, and Rui L. Aguiar. Computer Communications, 89-90:117--127, sep 2016. [ bib | DOI | http ]
The continuous flow of technological developments in communications and electronic industries has led to the growing expansion of the Internet of Things (IoT). By leveraging the capabilities of smart networked devices and integrating them into existing industrial, leisure and communication applications, the IoT is expected to positively impact both economy and society, reducing the gap between the physical and digital worlds. Therefore, several efforts have been dedicated to the development of networking solutions addressing the diversity of challenges associated with such a vision. In this context, the integration of Information Centric Networking (ICN) concepts into the core of IoT is a research area gaining momentum and involving both research and industry actors. The massive amount of heterogeneous devices, as well as the data they produce, is a significant challenge for a wide-scale adoption of the IoT. In this paper we propose a service discovery mechanism, based on Named Data Networking (NDN), that leverages the use of a semantic matching mechanism for achieving a flexible discovery process. The development of appropriate service discovery mechanisms enriched with semantic capabilities for understanding and processing context information is a key feature for turning raw data into useful knowledge and ensuring the interoperability among different devices and applications. We assessed the performance of our solution through the implementation and deployment of a proof-of-concept prototype. Obtained results illustrate the potential of integrating semantic and ICN mechanisms to enable a flexible service discovery in IoT scenarios.

 
Scalable semantic aware context storage. Mário Antunes, Diogo Gomes, and Rui L. Aguiar. Future Generation Computer Systems, 56:675--683, mar 2016. [ bib | DOI | http ]
The number of connected devices collecting and distributing real-world information through various systems, is expected to soar in the coming years. As the number of such connected devices grows, it becomes increasingly difficult to store and share all these new sources of information. Several context representation schemes try to standardize this information, but none of them have been widely adopted. In previous work we addressed this challenge, however our solution had some drawbacks: poor semantic extraction and scalability. In this paper we discuss ways to efficiently deal with representation schemes' diversity and propose a novel d-dimension organization model. Our evaluation shows that d-dimension model improves scalability and semantic extraction.

 
Smart Cloud of Things: An Evolved IoT Platform for Telco Providers. Mário Antunes, João Paulo Barraca, Diogo Gomes, Paulo Oliveira, and Rui L. Aguiar. Journal of Ambient Wireless Communications and Smart Environments (AMBIENTCOM), 1(1):1--24, 2016. [ bib | DOI | http ]
 
D3M: Multicast listener mobility support mechanisms over distributed mobility anchoring architectures. Sérgio Figueiredo, Seil Jeon, Diogo Gomes, and Rui L. Aguiar. Journal of Network and Computer Applications, 53:24--38, jul 2015. [ bib | DOI | http ]
The explosion in mobile data traffic is a driver for future network operator technologies, given its large potential to affect both network performance and generated revenue. The concept of distributed mobility management (DMM) has emerged in order to overcome efficiency-wise limitations in centralized mobility approaches, proposing not only the distribution of anchoring functions but also dynamic mobility activation sensitive to the applications needs. Nevertheless, there is not an acceptable solution for IP multicast in DMM environments, as the first proposals based on MLD Proxy are prone to tunnel replication problem or service disruption. We propose the application of PIM-SM in mobility entities as an alternative solution for multicast support in DMM, and introduce an architecture enabling mobile multicast listeners support over distributed anchoring frameworks in a network-efficient way. The architecture aims at providing operators with flexible options to provide multicast mobility, supporting three modes: the first one introduces basic IP multicast support in DMM; the second improves subscription time through extensions to the mobility protocol, obliterating the dependence on MLD protocol; and the third enables fast listener mobility by avoiding potentially slow multicast tree convergence latency in larger infrastructures, by benefiting from mobility tunnels. The different modes were evaluated by mathematical analysis regarding disruption time and packet loss during handoff against several parameters, total and tunneling packet delivery cost, and regarding packet and signaling overhead.

 
Privacy indata publishing for tailored recommendation scenarios. João M. Gonçalves, Diogo Gomes, and Rui L. Aguiar. Transactions on Data Privacy, 8(3):245--271, 2015. [ bib | http ]
Personal information is increasingly gathered and used for providing services tailored to user preferences, but the datasets used to provide such functionality can represent serious privacy threats if not appropriately protected. Work in privacy-preserving data publishing targeted privacy guarantees that protect against record re-identification, by making records indistinguishable, or sensitive attribute value disclosure, by introducing diversity or noise in the sensitive values. However, most approaches fail in the high-dimensional case, and the ones that don't introduce a utility cost incompatible with tailored recommendation scenarios. This paper aims at a sensible trade-off between privacy and the benefits of tailored recommendations, in the context of privacy-preserving data publishing. We empirically demonstrate that significant privacy improvements can be achieved at a utility cost compatible with tailored recommendation scenarios, using a simple partition-based sanitization method.

 
CloudThinking as an Intelligent Infrastructure for Mobile Robotics. Rui L. Aguiar, Diogo Gomes, João Paulo Barraca, and Nuno Lau. Wireless Personal Communications, 76(2):231--244, may 2014. [ bib | DOI | http ]
Mobile robotics is a transforming field that presents a varying set of challenges. The discussion on the autonomy of (self-powered) robots is not settled, and as the communication infrastructure evolves, centralized concepts become more attractive over distributed concepts. This paper presents the CloudThinking architecture applied to intelligent cloud-based robotic operation. CloudThinking offloads most of complex robotic tasks to a central cloud, which retrieves inputs from the environment as a whole in order to instruct the robots to perform its actions. CloudThinking is a natural approach to the orchestration of multiple specialized robotic systems, defining the best mechanisms for reaching a goal. Furthermore, this architecture provides a set of automatic features which can be useful for application developers. These features can fully exploit novel cloud tools development as it becomes available, providing a time-resilient infrastructure of easy upgrade. The resulting approach has the potential to create a different set of market for robotic application developers.

 
A Context-Aware Framework for Collaborative Activities in Pervasive Communities. Christopher Lima, Mário Antunes, Diogo Gomes, Rui Aguiar, and Telma Mota. International Journal of Distributed Systems and Technologies, 5(2):31--43, jan 2014. [ bib | DOI | http ]
Pervasive environments involve the interaction of users with the objects that surround them and also other participants. In this way, pervasive communities can lead the user to participate beyond traditional pervasive spaces, enabling the cooperation among groups taking into account not only individual interests, but also the collective and social context. In this study, the authors explore the potential of using context-aware information in CSCW application in order to support collaboration in pervasive environments. In particular this paper describes the approach used in the design and development of a context-aware framework utilizing users' context information interpretation for behaviour adaptation of collaborative applications in pervasive communities.

 
The business of things architecture. F. Cabral Pinto, P. Chainho, N. Pássaro, F. Santiago, D. Corujo, and D. Gomes. Transactions on Emerging Telecommunications Technologies, 24(4):441--452, jun 2013. [ bib | DOI | http ]
A revolution is happening that is triggered by a brave new world made by interconnected devices. The internet of things is already a reality that is creating new business opportunities across different industrial sectors. Communication service providers have a major opportunity to shape this reality by leading this transformation. For that, they need to evolve their existing architectures to enable a flexible creation of advanced services over distributed networks, interconnecting heterogeneous sensors and actuators. This paper presents an approach for telecoms to take advantage of the upcoming machine-to-machine markets and defines an advanced architecture able to withstand the demands of a new plethora of evermore clever and useful services.

 
MINDiT: A framework for media independent access to things. Daniel Corujo, Marcelo Lebre, Diogo Gomes, and Rui Aguiar. Computer Communications, 35(15):1772--1785, sep 2012. [ bib | DOI | http ]
Deploying smart environments often implies a plethora of co-existing devices and services, each with their own set of features, requirements and interfacing characteristics. These intricate scenarios are further exacerbated when such devices are coupled with networking capabilities, globalizing their interaction opportunities to create the so-called Internet of Things. In such interconnected heterogeneous environments, the joint operation of entities requires a flexible framework that enables and simplifies interfacing between elements. In this paper, we propose MINDiT, a framework that provides a common abstract interface towards the communication support with different entities. It incorporates cross-layer mechanisms inspired on the existing IEEE 802.21 technology, suitably modified to facilitate and optimize deployment in scenarios featuring both high-level, and low-powered network-restricted entities. MINDiT was validated through a prototype built over an open-source IEEE 802.21 implementation. We further compared its signaling impact against other solutions, and evaluated its performance over a smart environment featuring a multimedia scenario with multiple devices and services.

 
NGM2M. Daniel Corujo, Diogo Gomes, Filipe Cabral Pinto, Fernando Santiago, Paulo Chainho, and Nuno Pássaro. Revista Saber & Fazer Telecomunicações, pages 43--51, 2012. [ bib ]
Todos os indicadores apontam para um crescimento exponencial das comunicações máquina-a-máquina. A utilização da informação de uma panóplia de sensores, associada ao uso dos mais diversos atuadores, permite a criação de um mundo novo de aplicações que abrange os mais distintos sectores de atividade. Os ganhos operacionais, a economia de custos e a reinvenção de processos são alguns dos fatores-chave que contribuirão para a adoção deste novo paradigma. Atentos a este mercado, os operadores de telecomunicações multiplicam-se atualmente em iniciativas e estratégias para se posicionarem de forma mais abrangente na cadeira de valor, com o objectivo de suportar novos serviços diferenciadores que vão muito para além da simples disponibilização de conectividade. Este artigo visa a apresentação da arquitetura de uma plataforma horizontal de criação e disponibilização de serviços M2M, definida tendo por base os objetivos dos projetos Apollo e IoT.est, colmatando o fosso existente entre os diversos serviços e a heterogeneidade de redes e dispositivos, estimulando assim a criação de novos negócios.

 
A Cross-System Approach for Multimedia Services with IP Multicast in 4G Networks. Diogo Gomes, Rui L. Aguiar, and Susana Sargento. Wireless Personal Communications, 52(3):651--668, feb 2010. [ bib | DOI | http ]
The increased demand for multimedia services by mobile end users in recent years have driven both Broadcast and Wireless Network operators to develop new systems and architectures for the deployment of such services. The proposed solutions are nonetheless limited either in terms of QoS or Capabilities to deliver new interactive services. This paper highlights strengths and drawbacks of the existing technologies in terms of QoS, Security and Mobility. In order to fill the gap between current solutions we propose a new architecture that builds itself on the synergies created by a heterogeneous network made of existing delivering technologies, such as 3GPP/MBMS and DVB, where services can be delivered to end-users in the most appropriate way for end-users and operators alike. A prototype implementation is further described.

 
Quasi-omniscient Networks: Scenarios on Context Capturing and New Services Through Wireless Sensor Networks. Rui Aguiar and Diogo Gomes. Wireless Personal Communications, 45(4):497--509, jun 2008. [ bib | DOI | http ]
This paper addresses future scenarios for the telecommunications field, addressing the impact of three important research trends in computer networks: Context, Sensors and Wireless Networks. The proposed scenarios clearly highlight the possible synergies between the defined areas, and describe the role of Users and Network Operators in order to achieve the described goals. The potential danger of an over-encompassing network is identified, with a brief discussion on the challenges associated to the implementation of such a knowledge-aware communications network. The paper finalizes presenting a classification on the typical scenarios to be expected, and highlighting the associated challenges. It also presents a proposal on a scalable network infrastructure for Context processing.

 
IP-based content delivery over Next Generation Networks. Diogo Gomes, Filipe Pinto, Joao Goncalves, and Rui L Aguiar. International Journal of Internet Protocol Technology, 3(3):170, 2008. [ bib | DOI | http ]
Trends towards Next Generation Networks (NGN) are also changing the fundamental nature of TV services. Entertainment is becoming an increasingly participative experience, both with user feedback, and with user-generated content. Furthermore, the diversity of delivery mechanisms is increasing, reaching the mobile environment. The diversity of actors and technologies is now leading to a trend into IP-based content delivery, as a solution to heterogeneity management. We present an architecture for future environments, which bridges the gap between the content production and communication infrastructures, able to operate across different networks. This architecture resorts to the notion of Service Enablers deployed above evolved converged multimedia networks, based on the IP protocol. We demonstrated this architecture by laboratory prototyping.

 
Multicast/broadcast network convergence in next generation mobile networks. Justino Santos, Diogo Gomes, Susana Sargento, Rui Luis Aguiar, Nigel Baker, Madiha Zafar, and Ahsan Ikram. Computer Networks, 52(1):228--247, jan 2008. [ bib | DOI | http ]
The 3GPP Multimedia Broadcast Multicast Service (MBMS) aims to introduce group communications into the 3G networks. One of the current key challenges is how to evolve these incipient features towards the "beyond 3G vision" of a converged global network where multimedia content can be delivered over one or more selected broadcast transport bearers. This paper presents potential multicast/broadcast technologies convergence and discusses the issues and challenges in moving towards this next generation network vision from the viewpoint of evolving MBMS. (C) 2007 Elsevier B.V. All rights reserved.

 
Demonstrador de Mobilidade Heterogénea. Diogo Gomes, Nuno Duarte, and Nuno Sénica. Revista do Departamento de Electrónica e Telecomunicações da Universidade de Aveiro, 3(8), 2003. [ bib ]
Integrated in Computers and Telematics Engineer final project, a Heterogenity and Mobility Demo was setup, using as it base the European Project Moby Dick. Having the Demo setup further software packages were developed constituting an increased value to the Demo. All done several tests were performed on the Demo whose results are presented here

 
Síntese e Implementação de Circuitos Digitais Reconfiguráveis Dinamicamente. Diogo Gomes and Nuno Carvalho. Revista do Departamento de Electrónica e Telecomunicações da Universidade de Aveiro, 3(8), 2003. [ bib ]
The paper presents the results of the project proposed to the authors (who are the 4th year students of LECT) and shows how the specified problem has been solved. The description of the project and the basic requirements have been considered in the papers [1,2]

 
Sistema de apoio a organização e gestão de conferências cientificas ( CoW – Conference on the Web ). Diogo Gomes, João Paulo Barraca, and Nuno Sénica. Revista do Departamento de Electrónica e Telecomunicações da Universidade de Aveiro, 4(1), 2003. [ bib ]
This article intends to divulge software developed to help in the organization and management of Scientific Conferences on the Web (CoW). This Software package was developed by last year students of Eng. Computadores and Telemática in 5º year optional subject Ferramentas and Aplicacionais Multimédia

Conference Papers

 
{PASMO:} an open living lab for cooperative {ITS} and smart regions. Joaquim Ferreira, José Fonseca, Diogo Gomes, João Paulo Barraca, Bruno Fernandes, João Rufino, João Almeida, and Rui L Aguiar. In 2017 International Smart Cities Conference (ISC2) (ISC2 2017), Wuxi, P.R. China, sep 2017. [ bib ]
PASMO is a regional project aiming to bridge the gap between research and practice in the area of urban mobility support. It covers key access roads to the seaside villages of the Aveiro/Ilhavo region, in the center of Portugal, providing vehicular communications, regular WiFi access, and a myriad of useful mobility services (parking, bikes, jams, weather) under the umbrella of a smart region infrastructure dedicated to simply the involvement of industry in testing and developing new services.The infrastructure is currently being deployed, and the services will be operational by mid 2018.

 
Vehicular dataset for road assessment conditions. Mário Antunes, Diogo Gomes, João Paulo Barraca, and Rui L Aguiar. In 2017 International Smart Cities Conference (ISC2) (ISC2 2017), Wuxi, P.R. China, sep 2017. [ bib ]
The Internet of Things (IoT) is a very promising concept that by connecting numerous devices to the internet and extracting large sums of information (BigData) can enable the realisation of various futuristic scenarios. In order to develop and assess future applications and services, it is necessary the availability of datasets that can be used to train, test and cross validate.

Project SCoT (Smart Cloud of Things) has developed an M2M platform capable of collecting information from heterogeneous devices and collide that information in a large data repository. During its pilot phase, the project made the assessment of the road conditions in the region of Aveiro, Portugal. In this work we make the dataset used on the previous mentioned pilot publicly available. With this dataset our road assessment algorithm reached 80\\% accuracy in the task of pothole detection, other scenarios (that take into account vehicular speed, position and acceleration) can also be explored. The dataset was not pre-processed in anyway, the only transformation was made to protect the identity of the volunteers.

 
Secure decentralized IoT Infrastructure. Vasco Santos, Joao Paulo Barraca, and Diogo Gomes. In 2017 Wireless Days, pages 173--175, Porto, Portugal, mar 2017. IEEE. [ bib | DOI | http ]
Despite many Internet of Things (IoT) Infrastructures having been implemented in recent years, none of them is truly prepared for a global deployment, where failure tolerance and scalability are an essential requirement. This article presents an alternative concept for IoT Infrastructures, which focuses on enhancing the traditional centralized architecture, usually operated by a single entity, into a decentralized architecture featuring multiple business roles. We propose a dynamic and self-configurable infrastructure on top of a structured Peer-to-Peer network. In addition, a set of communication protocols are provided in order to support heterogeneous devices, as well as data access, streaming and persistence. It is also an important focus of our proposal to have mechanisms that guarantee the privacy and security of the information flow and storage.

 
Extracting knowledge from stream behavioural patterns. R. Jesus, M. Antunes, D. Gomes, and R. Aguiar. In IoTBDS 2017 - Proceedings of the 2nd International Conference on Internet of Things, Big Data and Security, 2017. [ bib ]
Copyright © 2017 by SCITEPRESS - Science and Technology Publications, Lda. All rights reserved. The increasing number of small, cheap devices full of sensing capabilities lead to an untapped source of information that can be explored to improve and optimize several systems. Yet, as this number grows it becomes increasingly difficult to manage and organize all this new information. The lack of a standard context representation scheme is one of the main difficulties in this research area (Antunes et al., 2016b). With this in mind we propose a stream characterization model which aims to provide the foundations of a new stream similarity metric. Complementing previous work on context organization, we aim to provide an automatic organizational model without enforcing specific representations.

 
Learning Semantic Features from Web Services. Mario Antunes, Diogo Gomes, and Rui Aguiar. In 2016 IEEE 4th International Conference on Future Internet of Things and Cloud (FiCloud), pages 270--275. IEEE, aug 2016. [ bib | DOI | http ]
 
Scalable semantic aware context storage. Mário Antunes, Diogo Gomes, and Rui L. Aguiar. Future Generation Computer Systems, 56:675--683, mar 2016. [ bib | DOI | http ]
The number of connected devices collecting and distributing real-world information through various systems, is expected to soar in the coming years. As the number of such connected devices grows, it becomes increasingly difficult to store and share all these new sources of information. Several context representation schemes try to standardize this information, but none of them have been widely adopted. In previous work we addressed this challenge, however our solution had some drawbacks: poor semantic extraction and scalability. In this paper we discuss ways to efficiently deal with representation schemes' diversity and propose a novel d-dimension organization model. Our evaluation shows that d-dimension model improves scalability and semantic extraction.

 
Smart Cloud of Things: An Evolved IoT Platform for Telco Providers. Mário Antunes, João Paulo Barraca, Diogo Gomes, Paulo Oliveira, and Rui L. Aguiar. Journal of Ambient Wireless Communications and Smart Environments (AMBIENTCOM), 1(1):1--24, 2016. [ bib | DOI | http ]
 
Semantic Features for Context Organization. Mario Antunes, Diogo Gomes, and Rui Aguiar. In 2015 3rd International Conference on Future Internet of Things and Cloud, pages 87--92. IEEE, aug 2015. [ bib | DOI | http ]
In recent years the technological world has grown by incorporating billions of small sensing devices, collecting and sharing real-world information. As the number of such devices grows, it becomes increasingly difficult to manage all these new information sources. There is no uniform way to share, process and understand context information. In previous publications we discussed efficient ways to organize context information that is independent of structure and representation. However, our previous solution suffers from semantic sensitivity. In this paper we review semantic methods that can be used to minimize this issue, and propose an unsupervised semantic similarity solution that combines distributional profiles with public web services. Our solution was evaluated against Miller-Charles dataset, achieving a correlation of 0.6.

 
TVPulse: Improvements on detecting TV highlightsin Social Networks using metadata and semanticsimilarity. Gomes Diogo Vilaça Afonso, Antunes Mário. In 14ª Conferência sobre Redes de Computadores, At Évora, Portugal, Evora, 2015. [ bib | http ]
Sharing live experiences in social networks is agrowing trend. That includes posting comments and sentimentsabout TV programs. Automatic detection of messages withcontents related to TV opens new opportunities for the industryof entertainment information.This paper describes a system that detects TV highlights in oneof the most important social networks - Twitter. Combining Twit-ter's messages and information from an Electronic ProgrammingGuide (EPG) enriched with external metadata we built a modelthat matches tweets with TV programs with an accuracy over80%. Our model required the construction of semantic profilesfor the Portuguese language. These semantic profiles are usedto identify the most representative tweets as highlights of a TVprogram. Measuring semantic similarity with those tweets it ispossible to gather other messages within the same context. Thisstrategy improves the recall of the detection. In addition wedeveloped a method to automatically gather other related webresources, namely Youtube videos. TVPulse: Improvements on detecting TV highlights in Social Networks using metadata and semantic similarity. Available from: https://www.researchgate.net/publication/284162175_TVPulse_Improvements_on_detecting_TV_highlights_in_Social_Networks_using_metadata_and_semantic_similarity [accessed Feb 23, 2016].

 
TVPulse: detecting TV highlights in Social Networks. A Vilaça, M Antunes, and D G Gomes. In 10th Conference on Telecommunications Conftele, volume NA, pages NA -- NA, 2015. [ bib ]
 
Semantic-Based Publish/Subscribe for M2M. Mario Antunes, Diogo Gomes, and Rui Aguiar. In 2014 International Conference on Cyber-Enabled Distributed Computing and Knowledge Discovery, pages 256--263. IEEE, oct 2014. [ bib | DOI | http ]
 
Scalable Semantic Aware Context Storage. Mario Luis Pinto Antunes, Diogo Nuno Pereira Gomes, and Rui Luis Andrade Aguiar. In 2014 International Conference on Future Internet of Things and Cloud, pages 152--158. IEEE, aug 2014. [ bib | DOI | http ]
In recent years the Internet has grown by incorporating billions of small devices, collecting real-world information and distributing it though various systems. As the number of such devices grows, it becomes increasingly difficult to manage all these new information sources. Several context representation schemes have tried to standardize this information, however none of them have been widely adopted. Instead of proposing yet another context representation scheme, we discuss an efficient way to deal with this diversity of representation schemes. We define the basic requirements for context storage systems, analyse context organizations models and propose a new context storage solution. Our solution implements an organizational model that improves scalability, semantic extraction and minimizes semantic ambiguity.

 
A Facebook event collector framework for profile monitoring purposes. Hugo Fonseca, Eduardo Rocha, Paulo Salvador, Antonio Nogueira, and Diogo Gomes. In 2014 IEEE Symposium on Computers and Communications (ISCC), pages 1--6, Funchal, jun 2014. IEEE. [ bib | DOI | http ]
Social networks have recently emerged to become vital tools for information and content dissemination among connections. Indeed, the immense increase of the number of users of Facebook made it rise to become the largest existing social network with more than 1.2 billion active users. However, these numbers also rose the attention of hackers and attackers who aim at propagating malware and viruses for obtaining confidential information regarding social network users. In this manner, it is crucial that each Facebook user is able to easily access, control and analyse the information shared on the corresponding profile so that profile usage deviations can be more efficiently detected. However, despite the fact that Facebook allows an analysis of all user actions through the Timeline Review, this information is not comprehensively organized and there is no statistical analysis of the user generated data. In this paper, we propose a novel framework comprising a Facebook event collector, which by being provided with an authentication token for a user profile obtained through a Facebook application developed for this purpose, collects all the corresponding posted information and stores it in a relational database for a posteriori analysis. Through the graphical interface of the developed application, users can access all stored information in a comprehensible manner, according to the type of event, thus facilitating the analysis of the user's behaviour. By storing each event with the corresponding timestamp, we are able to perform an efficient and comprehensive analysis of all posted contents and compute statistical models over the obtained data. In this manner, we can create a notion of normal usage profile and detect possible deviations which may be indicative of a compromised user account.

 
User-hosted SOA infrastructure over XMPP. Joao M. Goncalves and Diogo Gomes. In 2014 IEEE Symposium on Computers and Communications (ISCC), pages 1--6, Funchal, jun 2014. IEEE. [ bib | DOI | http ]
The proliferation of user-owned connected devices has brought value to mobile application developers, which can make use of locally-available sensors and capabilities and send their information to the web, centralizing the data flows. A more distributed approach would have device capabilities offered directly on the network as services hosted by the user. These pervasive user-hosted services could be made discoverable and available over a public federated service infrastructure. The infrastructure would provide transport over an identity layer, where endpoints are addressed by their identities instead of network identifiers, and on top of which services can be exposed to be consumed by trusted friends or anonymous users, as the hosting user prefers. The work presented in this paper explores the possibility of implementing such a distributed social Service-Oriented Architecture (SOA) over Extensible Messaging and Presence Protocol (XMPP). This SOA, which would expose re-usable coarse-grained software components in a service ecosystem, differs from traditional SOA because it attempts to counter the centralization existing services, in favour of a fully-distributed service ecosystem where each peer can behave both as service consumer and provider. Finally, an analysis is done on how suitable XMPP is to serve as a base protocol for such infrastructure.

 
Unified Platform for M2M Telco Providers. Aguiar Rui L. Antunes Mário, Barraca João Paulo , Gomes Diogo, Oliveira Paulo. In Ramón Hervás, Sungyoung Lee, Chris Nugent, and José Bravo, editors, Ubiquitous Computing and Ambient Intelligence. Personalisation and User Adapted Services, volume 8867 of Lecture Notes in Computer Science, pages 436--443, Cham, 2014. Springer International Publishing. [ bib | DOI | http ]
Although many environments are powered by M2M solutions, users do not have a simple way to gather their collective knowledge and program devices' behaviour. Also, Telco providers still lack proper components for enabling integrated services over their networks. We present the final architecture of the APOLLO project, which delivers a enhanced M2M platform encompassing sensors, management and applications platform for a major Telco provider. APOLLO builds on top of ETSI M2M specifications and rich service execution environments providing easy orchestration of services to end-users.

 
Benchmarking the Performance of Hypervisors on Different Workloads. Devi Bhukya, Carlos Gonçalves, Diogo Gomes, and Rui L. Aguiar. In Proc. The Ninth International Conference on Software Engineering Advances (ICSEA 2014), Nice, France, 2014. [ bib | http ]
Many organizations rely on a heterogeneous set of applications in virtual environment to deliver critical services to their customers. Different workloads utilize system resources at different levels. Depending on the resource utilization pattern some workloads may be better suited for hosting on a virtual platform. This paper discusses a novel framework for benchmarking the performance of Oracle database workloads such as Online Analytical Processing (OLAP), Online Transaction Processing (OLTP), Web load and Email on two different hypervisors. Further, Design of Experiments (DoE) is used to identify the significance of input parameters, and their overall effect on two hypervisors, which provides a quantitative and qualitative comparative analysis to customers with high degree of accuracy to choose the right hypervisor for their workload in datacenters.

 
A Facebook Event Collector Framework for Profile Monitoring Purposes. Hugo Fonseca, Eduardo Rocha, Paulo Salvador, António Nogueira, and Diogo Gomes. In IEEE, editor, 19th IEEE Symposium on Computers and Communications (IEEE ISCC 2014), pages 1--6, Madeira, Portugal, 2014. [ bib | DOI | http ]
Social networks have recently emerged to become vital tools for information and content dissemination among connections. Indeed, the immense increase of number of users of Facebook made it rise to become the largest existing social network with more than 1.2 billion active users. However, these numbers also rose the attention of hackers and attackers who aim at propagating malware and viruses for obtaining confidential information regarding social network users. In this manner, it is crucial that each Facebook user is able to easily access, control and analyse the information shared on the corresponding profile so that profile usage deviations can be more efficiently detected. However, despite the fact that Facebook allows an analysis of all user actions through the Timeline Review, this information is not comprehensively organized and there is no statistical analysis of the user generated data. In this paper, we propose a novel framework comprising a Facebook event collector, which by being provided with an authentication token for a user profile obtained through a Facebook application developed for this purpose, collects all the corresponding posted information and stores it in a relational database for \textit{a posteriori} analysis. Through the graphical interface of the developed application, users can access all stored information in a comprehensible manner, according to the type of event, thus facilitating the analysis of user behaviour. By storing each event with the corresponding timestamp, we are able to perform an efficient and comprehensive analysis of all posted contents and compute statistical models over the obtained data. In this manner, we can create a notion of normal usage profile and detect possible deviations which may be indicative of a compromised user account.

 
Context Storage for M2M Scenarios. Mário Antunes, Diogo Gomes, and Rui L Aguiar. In IEEE ICC 2014 - Selected Areas in Communications Symposium (ICC'14 SAC), pages 3664--3669, Sydney, Australia, 2014. IEEE. [ bib | DOI | http ]
As the number of environmental sensors grows, it becomes increasingly difficult to manage, store and process all these sources of information. Several context representation schemes try to standardize this information, however none of them have been widely adopted. Instead of proposing yet another context representation scheme, we discuss efficient ways to deal with this diversity of representation schemes. We defined the basic requirements for flexible context storage systems, proposed an implementation and compared our implementation against two other approaches. Our solution provides more value than the remaining solutions without suffering a significant decrease in performance.

 
User-Hosted SOA Infrastructure over XMPP. João Gonçalves and Diogo Gomes. In 19th IEEE Symposium on Computers and Communications (IEEE ISCC 2014), Madeira, Portugal, 2014. [ bib | DOI ]
The principles of Service-Oriented Architecture (SOA) argue for the design of systems composed of re-usable coarse-grained software components which consume and provide services in a service ecosystem. Despite being commonly mentioned in an enterprise context, these are very present in the web - most web applications expose some of their data via APIs, which are then used by other web and mobile applications. The proliferation of user-owned connected devices has brought value to mobile application developers which can make use of locally-available sensors and capabilities and send their information to the web, centralizing the data flows. A more distributed approach would have device capabilities offered directly on the network as services hosted by the user. These pervasive user-hosted services could be made discoverable and available over a public federated service infrastructure. The infrastructure would provide transport over an identity layer, where endpoints are addressed by their identities instead of network identifiers, and on top of which services can be exposed to be consumed by trusted friends or anonymous users, as the hosting user prefers. The work presented in this paper explores the possibility of implementing a distributed social SOA over Extensible Messaging and Presence Protocol (XMPP). It differs from traditional SOA because it attempts to counter relative centralization of the web, in favour of a fully-distributed service ecosystem where each peer can behave both as service consumer and provider. Finally, an analysis is done on how suitable XMPP is to serve as a base protocol for such infrastructure.

 
Towards behaviour inference in smart environments. Mario Antunes, Diogo Gomes, and Rui Aguiar. In Proceeding of the 2013 Conference on Future Internet Communications, CFIC 2013, pages 1--8. IEEE, may 2013. [ bib | DOI | http ]
Smart environments are physical places that are richly and invisibly populated with sensors, actuators and computational elements. The objective of such environments is to adapt themselves to its users in order to increase their comfort and usefulness. This paper proposes a platform, named APOLLO, capable of inferring behaviour rules from a smart environment and apply them to provide an intelligent space. The APOLLO platform is built upon a Service Oriented Architecture (SOA), in which collected context information is used to infer behaviour rules though statistical and machine learning techniques. The proposed platform is to be deployed in a home automation scenario.

 
A Context-aware Framework For CSCW Applications In Enterprise Environments. Christopher V Lima, Mário Antunes, Diogo Gomes, and Rui L Aguiar. In Eva Kasparova Piet Kommers and Nik Bessis, editors, IADIS International Conference Collaborative Technologies 2013 (part of MCCSIS 2013), pages 11--18. iadis, 2013. [ bib | http ]
Future pervasive environments will take into consideration physical and digital social relationships. Nowadays it is important to use collective intelligence, where the interpretation of context information can be harnessed as input for context-aware applications, especially for group collaboration. For collaborative applications this represents opportunities, but also new challenges in terms of using collective information for adaptability and personalization in pervasive environments. This paper presents the challenges in design and development of a context-aware framework CSCW supporting pro-behaviour capabilities in pervasive communities.

 
Social Awareness in Pervasive Communities for Collaborative Work. Christopher V Lima, Mário Antunes, Diogo Gomes, and Rui Luis Aguiar. In Workshop Proceedings of the 9th International Conference on Intelligent Environments, pages 110--115, Athens, Greece, 2013. IOS Press. [ bib | DOI | http ]
Future pervasive environments will take into consideration physical and digital social relations. Nowadays it is important use to collective intelligence, where the interpretation of context information can be harnessed as input for context-aware applications, especially for group collaboration. The use of collective intelligence represents new possibilities but also new challenges in terms of collective information for adaptability and personalization in intelligent environments. This paper presents a collaborative context-aware framework focusing on social matching capabilities for session formation in collaborative activities.

 
Demonstrating the AMazING panel. João Martins, João Paulo Barraca, Diogo Gomes, and Rui L. Aguiar. Proceedings of the seventh ACM international workshop on Wireless network testbeds, experimental evaluation and characterization - WiNTECH '12, page 89, aug 2012. [ bib | DOI | http ]
The Internet, and networks in general, are in many ways part of our daily life. As their usage increases, their faults and limita- tions also become more apparent, motivating network researchers to evaluate and develop new solutions anticipating future scenar- ios and overcoming the challenges identified. These challenges vary across a wide range of networking areas, from traffic opti- mization in telecom operators, to scalability in wide area networks and broadband multimedia streaming, or even to the contextualiza- tion of communications in order to optimize usage. For researchers to create reliable network solutions, able to be included in our ev- ery day life, these solutions must be carefully designed, tested, and then put into a cycle of successive refinement. Currently, there are some testbed management systems available. The core of most existent solutions can be reduced to a couple of shell scripts to operate the testbed resources, without the proper support for experiment automation. Running experiments is thus possible and flexible, but cumbersome, labor intensive, and error prone. The existent solutions lack proper graphical interfaces fa- cilitating user interaction, while centralizing the whole process of configuring experiments, reserving resources, scheduling, and col- lecting its results. Furthermore, collaboration of multiple parties is vital in the current research environment. Experiment results must be shared with a closed number of peers in order to allow a better analysis and a more solid validation inside research terms.

 
Experimentation made easy with the AMazING panel. João Martins, João Paulo Barraca, Diogo Gomes, and Rui Luis Aguiar. In Proceedings of the seventh ACM international workshop on Wireless network testbeds, experimental evaluation and characterization - WiNTECH '12, page 11, New York, New York, USA, aug 2012. ACM Press. [ bib | DOI | http ]
Experimental testbeds for evaluating solutions in computer net- works, are today required as a complement to simulation and emu- lation. As these testbeds become larger, and accessible to a broader universe of the research community, dedicated management tools become mandatory. These tools ease the complex management of the testbed specific resources, while providing an environment for researchers to define their experiments with large flexibility. While there are currently several management tools, the research commu- nity is still lacking tools that smooth the experimentation workflow. These were key aspects that we considered when developing the management infrastructure for our wireless testbed[4] (AMazING). We developed a experimentation support framework supported by an attractive GUI, automation and scripting capabilities, as well as experiment versioning and integrated result gathering and analysis.

 
Furthering media independence mechanisms for Future Internet enablement. Daniel Corujo, Marcelo Lebre, Diogo Gomes, and Rui L. Aguiar. In 2012 IEEE International Conference on Communications (ICC), pages 6845--6849, Ottawa, Canada, jun 2012. IEEE. [ bib | DOI | http ]
The utilization of Media Independent Handover (MIH) mechanisms, such as the ones provided by the IEEE802.21 standard, allow the abstraction of control and information querying primitives of different wireless access technologies, using a common interface. This not only simplifies the design of high-level entities interfacing with said technologies, but by providing a transport protocol for that interface, such primitives can be used to extend controlling mechanisms towards remote entities. However, the standard only employs such flexible and abstraction capabilities towards handover optimization and facilitation scenarios. In this paper, we take advantage of the flexible design of the MIH mechanisms, and propose evolutions over their base design, allowing their integration into the areas of Internet Multimedia Optimization and the Internet of Things.

 
Low-latency privacy-enabled Context Distribution Architecture. Joao M. Goncalves, Diogo Gomes, and Rui Aguiar. In 2012 IEEE International Conference on Communications (ICC), pages 1917--1922, Ottawa, Canada, jun 2012. IEEE. [ bib | DOI | http ]
As personal information and context sharing applications gain traction more attention is drawn to the associated privacy issues. These applications address privacy using an unsatisfactory {"}whitelist{"} approach [1] [2], similar to social networks {"}friends{"}. Some of them also link location publishing with user interaction which is also a form of privacy control - the user has to explicitly say where he is. There are a few automatic location based-services (LBS) that track the user [3], but without more adequate privacy protection mechanisms they enable even bigger threats to the user. On previous work, an XMPP-based Context Distribution Architecture was defined [4], more suitable for the distribution of frequently changing context than other systems because it is based on the publish-subscribe pattern. In this paper the authors present an extension to this architecture that allows for the introduction of a complex degree of access control in context distribution. The devised changes enable the system to consider a number of interesting context privacy settings [1] for context distribution control. Also, this control must be enforced in a way that it doesn't interfere with the real-time nature of the distribution process. After describing the enhancements to the architecture, a prototype of the system is presented. Finally, the delivery latency and additional processing introduced by the access control components is estimated by testing it against the existing system.

 
Pervasive CSCW for smart spaces communities. Christopher Lima, Diogo Gomes, and Rui Aguiar. In 2012 IEEE International Conference on Pervasive Computing and Communications Workshops, pages 118--123, Lugano, Switzerland, mar 2012. IEEE. [ bib | DOI | http ]
Future pervasive environments will take into consideration not only individual users' interest, but also social relationships. In today's scenarios, the trend is to make use of collective intelligence, where the interpretation of context information can be harnessed as input for pervasive systems. Therefore, social CSCW applications represent new challenges and possibilities in terms of use of group context information for adaptability and personalization in pervasive computing. The objective of this paper is to present two enterprise scenarios that support collaboration and adaption capabilities through pervasive communities combined with social computing. Collaborative applications integrated with pervasive communities can increase the activity's quality of the end user in a wide variety of tasks.

 
An Architecture for the Future Business of Things. Filipe Cabral Pinto, Paulo Chainho, Nuno Pássaro, Fernando Santiago, Daniel Corujo, and Diogo Gomes. In Proc. 2012 International Workshop on M2M Communication Technologies and Systems, Wuxi, China, 2012. [ bib | .pdf ]
A brave new world made of interconnected smart devices will soon revolutionize the world. The application of the Internet of Things vision will foster the creation of new businesses across different industrial sectors. Communication Service Providers need to set the pace of this change if they want to lead this transformation. They need to both leverage and evolve their architectures in order to support a flexible creation of innovative services over distributed networks, linking heterogeneous sensors and actuators. This paper presents the roles of the telecoms on the upcoming machine-to-machine markets and devises an advanced architecture able to withstand the demands of a new plethora of evermore clever and useful services.

 
Architecture for orchestration of M2M services | ATNoG - Advanced Telecommunications and Networks Group. Gustavo Pires, Mário Antunes, Daniel Corujo, Diogo Gomes, João Paulo Barraca, and Rui L. Aguiar. In Diogo Gomes and Paulo Salvador, editors, CRC 2012: 12ª Conferência sobre Redes de Computadores, pages 112--119, Aveiro, 2012. Universidade de Aveiro. [ bib | http ]
The past few years, miniaturization has allowed usto imbue computers into everyday devices. This in turn hasenabled these devices to communicate with each other, and in doing so, allows us to collect a wealth of information, moreaccurately and with greater availability than ever before. Thisphenomenon is known as the Internet of Things. It allows smart environments to truly behave in an intelligent manner by using information collected from the devices mentioned above. However, it's necessary to model how the gathered data will influence the behavior of a smart environment. This open problem can be approached as a machine to machine (M2M) orchestration.In this paper we present a new architecture for M2Morchestration. This new architecture will be based around aplatform that creates orchestration processes through a graphical interface. Through this interface a business process execution language (BPEL) service will be made and deployed on an enterprise service bus (ESB). Alongside this, we are also developing a collection of services that will be used for the purposes of implementing a smart environment.

 
EMICOM: Enhanced Media Independent COnnection Manager. André Prata, Daniel Corujo, Pedro Gonçalves, and Diogo Gomes. In Diogo Gomes and Paulo Salvador, editors, CRC 2012: 12ª Conferência sobre Redes de Computadores, pages 38--46, Aveiro, 2012. Universidade de Aveiro. [ bib | http ]
With the increasing amount of mobile interfaces combining different kinds of access technologies, ranging from Wi-Fi to 3G and LTE, the integration of flexible and mediaindependent link control mechanisms becomes of paramount importance. By employing an abstract way of obtaining access link status information and exercising control over the network interface operations, these control mechanisms become able to optimize device connectivity and network attachment. This paper presents EMICOM, an Enhanced Media Independent COnnection Manager framework where a GNU/Linux Network Manager and Link Service Access Points for the IEEE 802.3 and 802.11 technologies were implemented and integrated through crosslayer Media Independent Handover (MIH) mechanisms from the IEEE 802.21 standard. Through an open-source implementation of the framework, the (MIH) command set capabilities are extended, allowing the support of network association and authentication, as well as Layer 3 services such as IP configuration, providing a generic solution for optimal network connectivity management.

 
Towards a Cloud Service Broker for the Meta-Cloud. Carlos Gonçalves, David Cunha, Pedro Neves, Pedro Sousa, João Paulo Barraca, and Diogo Gomes. In Diogo Gomes and Paulo Salvador, editors, CRC 2012: 12ª Conferência sobre Redes de Computadores, pages 7--13, Aveiro, 2012. Universidade de Aveiro. [ bib | http ]
Cloud Computing provides computing resources, middleware and (web-based) software on an on-demand basis. This model helps customers saving costs and allows access to the latest technology. With the exponential growth of IT companies offering cloud services, deploying applications to the cloud has become a complex task to engage. Almost each and every provider has its own terminology, providers do not share the same (or even similar) API, and costs of operation greatly diverge according to provider, region or availability. This paper propounds a Cloud Service Broker (CSB), and describes an early prototype, where users are, intelligently and autonomously, aid to deploy, manage, monitor and migrate their applications in a cloud of clouds. A single API is required to orchestrate the whole process in tandem with two truly decoupled managers: a Platform as a Service Manager (PaaS Manager) and an Infrastructure as Service Manager (Iaas Manager). Users also interact with the CSB through a Web portal and a command-line interface.

 
Sensor context information for energy-efficient optimization of wireless procedures. Daniel Corujo, Marcelo Lebre, Diogo Gomes, and Rui L. Aguiar. In 2011 IEEE 22nd International Symposium on Personal, Indoor and Mobile Radio Communications, pages 1010--1014, Toronto, Canada, sep 2011. IEEE. [ bib | DOI | http ]
The wide deployment of Wireless Local Area Networks (WLAN) we are witnessing today increases connectivity opportunities for mobile terminal devices, such as smartphones. However, continuous scanning for WLAN points of attachment can be a power exhausting mechanism for such battery-powered devices. These mobile devices, besides being equipped with different wireless access interfaces, are also coupled with sensors such as accelerometer, GPS, luminance and magnetic compass. In fact, sensors are increasingly being coupled into different devices and environments and are able to convey sensing information through networks into decision entities able to optimize different processes. In this paper we propose a framework where media independent sensing information is used to enhance wireless link management towards energy-efficiency. This framework enables the dissemination of sensing information towards local and remote decision entities, enhancing other processes (e.g. mobility) with sensing information in order to provide true Ambient Intelligence scenarios. We introduce this framework into a wireless management scenario able to provide energy-efficient optimal network connectivity.

 
A framework for flexible sensor information dissemination. Daniel Corujo, Marcelo Lebre, Diogo Gomes, and Rui Aguiar. In 2011 International Conference on Distributed Computing in Sensor Systems and Workshops (DCOSS), pages 1--6, Barcelona, Spain, jun 2011. IEEE. [ bib | DOI | http ]
The integration of the digital world into every aspect of our lives is becoming more and more preeminent. Nowadays, not only humans but also devices and the environments where we dwell are also able to provide their own information, through the usage of sensors. Through their interconnection over communication networks, sensors enable Ambient Intelligent scenarios achieving a true Internet of Things, and crossing the gap between computer systems and the real world. However, the different sensing devices and information generated by them, are of such disparate nature that it becomes increasingly difficult to access and make use of such heterogeneous data. In this paper, we propose a framework which not only considers a media independent information access to sensors and their supplied data, but is also flexible enough to configure and provide different means to best transport collected sensor information via wireless gateways, facilitating its deployment in different scenarios. We demonstrate its usefulness by providing a throughput efficient approach towards the collection and dissemination of sensing data, through sensing information compression and aggregation of multiple sources.

 
A Framework for the Connectivity of an Internet of Things. Daniel Corujo, Marcelo Lebre, Diogo Gomes, and Rui L. Aguiar. In IEEE Sensors, pages 643--646, Limerick, Ireland, 2011. [ bib | DOI | http ]
The evolution of telecommunications has allowed the coupling of networking features to an ever-increasing plethora of devices, enabling their connectivity and berthing of an Internet of Things (IoT). However, the assorted nature of such “things” implies disparate specifications, requirements and interfacing, for interaction with high-level decision modules, services and agents involved in the most distinct kind of scenarios. The joint operation of all networkable things in a truly integrated IoT vision requires a flexible framework able to facilitate interfacing with different elements and concepts. In this paper we present a framework that builds over the concept of Media Independence, further enhancing it to encompass the abstraction of different “things”, by providing the means for accessing their different interfacing procedures. We highlight the feasibility and flexibility of this framework by introducing it into an IoT scenario, enabling a flexible way for interface retrieval and control of different entities, paving the way for a truly universal and dynamic connectivity vision.

 
Media Independent Transport Service for Ambient Intelligence. Daniel Corujo, Marcelo Lebre, Diogo Gomes, and Rui L. Aguiar. In Conferência sobre Redes de Computadores, Coimbra, Portugal, 2011. [ bib | http ]
The evolution on ambient intelligence technologies, such as sensor networks, propelled a universe of very diverse types of both data and hardware equipment creating one of the most heterogeneous network environments. This diversity brings to light the main issue we aim to address in this paper: the need for a common ground that enables communications between the different heterogeneous equipments and technologies. Starting from the well-established IEEE 802.21 Media Independent Handover standard, we propose its mechanisms and structure to be extended to provide the needed common ground for communication in ambient intelligence scenarios. In this work, we extend 802.21 to include sensor information, enabling different types of equipment and network technologies to communicate with each other under a common standard contributing to a truly heterogeneous network framework. To conclude, we address its viability through a comparison with other known solutions for communication on sensing devices.

 
Context Storage Using NoSQL. Nuno Santos, Oscar Pereira, and Diogo Gomes. In Conferência sobre Redes de Computadores, 2011. [ bib | http ]
With the ubiquity and pervasiveness of mobile com- puting, together with the increasing number of social networks, end-users have learned to live and share all kinds of information about themselves. As an example, Facebook reports that it has currently 500 million active users, 200 million of which access its services on mobile systems; moreover, users that access Facebook through mobile applications are twice as active as non-mobile users, and it is used by 200 mobile operators in 60 countries [1]. More specific mobile platforms such as Foursquare, which unlike Facebook only collects location information, reports 6.5 million users worldwide, and also has a mobile presence (both with a web application and iPhone / Android applications) [2]. Context- aware architectures intend to explore this increasing number of context information sources and provide richer, targeted services to end-users, while also taking into account arising privacy issues. While multiple context management platform architectures have been devised [3], this paper focuses primarily on Context- Broker-based architectures, such as the ones proposed in the projects Mobilife [4] and C-Cast [5]. More specifically, it focuses on the context management platform XCoA [6]. This platform uses XMPP for its main communication protocol, and publishes context information in a Context-Broker. This context informa- tion is provided by Context-Agents, such as mobile terminals, sensor networks and social networks. Due to the nature of the XMPP protocol, the context information is provided in XML form. This paper proposes the usage of a NoSQL storage system for the purpose of context information storage and retrieval in an XMPP broker-based context platform such as XCoA, together with a full-text searching engine. Through a comparison made through prototypes, the paper clearly demonstrates the advantages of NoSQL storage systems applied to the area of Context Management.

 
Context Transport based on 802.21 MIH protocol. Lebre Marcelo, Daniel Corujo, Diogo Gomes, and Rui L Aguiar. In Proc. 1 CNRS 2011 - Conference on Wireless Sensor Networks, Coimbra, Portugal, 2011. [ bib ]
Sensor networks, along with the sensorial output from their nodes, provide an information source to enhance and enrich upper layers mechanisms. The 802.21 MIH protocol provides a cross layer framework that can be extended for sensor information transport. At the same time, it creates an abstraction layer that removes hardware and software specificity from sensor nodes. On a higher level of the network stack, the XMPP protocol also provides an upper layer solution for content syndication on a platform with global access availability. We present a framework which integrates a cross-layer abstraction approach towards sensor devices of different families, while enabling the integration of media-independent sensor information into context consumers with the aim of optimizing network management, as well as application operation and usability. The work presented was also part of the first author's MsC dissertation.

 
XMPP based Context Management Architecture. Diogo Gomes, Joao M. Goncalves, Ricardo Otero Santos, and Rui Aguiar. IEEE, Miami, Florida, USA, dec 2010. [ bib | DOI | http ]
In recent years several authors and projects have addressed the need for an architecture for collecting and managing context information. Most of the approaches have either been purely based in middlewares unable to address the heterogeneity of components and services platforms, or have been built around Web based technologies that are unable to cope with the realtime and reactiveness requirements that many context- aware use cases have. In this paper the authors propose a new Context Management Architecture able to solve these problems. Furthermore, this architecture, exploring the XMPP protocol, can be used as the basis for new developments in this area.

 
Context-Aware Content Casting. Telma Mota, Massimo Valla, and Diogo Gomes. In NEM, Barcelona, Spain, 2010. [ bib | .pdf ]
This paper presents a context-aware content distribution architecture based on both a generic context framework and a service platform composed of smart service enablers which are reused by different applications. A general description of the architecture components is presented emphasising the context framework, its main features and functionalities. To prove the proposed concepts and evaluate the architecture three applications have been developed targeting different types of content and usage scenarios in Public Smart Spaces.

 
AMazING - Advanced Mobile wIreless Network playGround. Joao Paulo Barraca, Diogo Gomes, and Rui L Aguiar. In International Conference on Testbeds and Research Infrastructures for the Development of Networks & Communities and Workshops, Berlin, Germany, 2010. [ bib | DOI | http ]
We describe a wireless testbed composed by 24 wireless nodes that can be used to perform a broad range of studies in the area of next generation networks. This paper addresses the difficulties and constrains faced by the authors throughout the deployment process of such testbed. Flexibility and controllability were key concerns driving the testbed design. The testbed can be remotely managed through a series of remotely accessible web services performing low-level management. Validation results are presented, showing the interference levels of the testbed as well as its maximum throughput capabilities.

 
Characterization of Unplanned Metropolitan Wireless Networks, Filipe Dias, João Paulo Barraca, Diogo Gomes, and Rui L. Aguiar. 2010. [ bib | http ]
Mobile Internet penetration has grown steadily over the last few years. Although most of today's users have access through their 3G Mobile Operators, there are still regions that are under-covered for various reasons. Wireless Mesh Networks (WMN) can play an important role by providing the means to fully cover those underserved regions. Due to their intrinsic nature, WMN require a critical mass of nodes belonging to the mesh in order to be effective. In this paper we present a study conducted in Aveiro, Portugal which intends to draw some conclusions on the feasibility of deploying a WMN in small to medium cities based on the cooperation of its inhabitants and on off-the-shelf wireless equipment.

 
The applicability of context-based multicast - A shopping centre scenario. Thomas Wozniak, Katarina Stanoevska-Slabeva, Diogo Gomes, and Hans D. Schotten. In Stiller Burkhard, editor, Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), volume 6236 LNCS, pages 101--108, Amsterdam, The Netherlands, 2010. Springer-Verlag Berlin, Heidelberg ©2010. [ bib | DOI | http ]
This paper analyzes the applicability of context-based multicast con- tent distribution (CBMCD) on the example of realistic push- and video-based mobile advertising services at a shopping centre. The technical results of the simulation of the service scenario show that CBMCD significantly reduces the number of unicast streams and the total volume of traffic in the network. The results of the financial analysis show that these technical benefits can be translated into considerable financial benefits due to costs savings. Taken together, these results suggest that CBMCD can be an efficient, cost-saving network traffic management approach and the basis for lucrative push services.

 
Characterization of Unplanned Metropolitan Wireless Networks. Filipe Dias, João Paulo Barraca, Diogo Gomes, and Rui L Aguiar. In 10th Conferência sobre Redes de Computadores, Braga, Portugal, 2010. [ bib | http ]
Mobile Internet penetration has grown steadily over the last few years. Although most of today's users have access through their 3G Mobile Operators, there are still regions that are under-covered for various reasons. Wireless Mesh Networks (WMN) can play an important role by providing the means to fully cover those underserved regions. Due to their intrinsic nature, WMN require a critical mass of nodes belonging to the mesh in order to be effective. In this paper we present a study conducted in Aveiro, Portugal which intends to draw some conclusions on the feasibility of deploying a WMN in small to medium cities based on the cooperation of its inhabitants and on off-the-shelf wireless equipment.

 
Evaluation of policy-based admission control mechanisms in NGN. Pedro Goncalves, Ricardo Azevedo, Diogo Gomes, Jose Luis Oliveira, and Rui L Aguiar. In 2009 International Conference on Telecommunications, pages 137--142, Marrakech, Morocco, may 2009. IEEE. [ bib | DOI | http ]
The 3GPP consortium proposed in the release 7 of the IP Multimedia Subsystem (IMS) a Diameter interface for the resource admission communication process replacing the previous COPS solution. Although both academic and industry communities have deeply debate the advantages and disadvantages of each protocol, its impact in NGN may have not been thoroughly quantified. This paper compares both protocols in terms of messages exchanged between network entities, and of bandwidth requirements during the admission control process. Based on general network operator environment characteristics, we present several exploitation scenarios where it is analyzed the scalability and adequacy of each protocol.

 
Deploying and testing a NGN testbed IST-daidalos testbed. Diogo Gomes, Alfredo Matos, Emanuel Fonseca, and Rui Aguiar. In 2009 5th International Conference on Testbeds and Research Infrastructures for the Development of Networks & Communities and Workshops, pages 1--6, Washington, USA, apr 2009. IEEE. [ bib | DOI | http ]
In the last 3 years a medium size NGN testbed was deployed at the Instituto de Telecomunicacoes of Aveiro in order to support the validation of the project IST-Daidalos. This paper intends to describe not only the work done in order to setup and maintain this testbed but also to elucidate the community of some of the caveats of creating and managing such a testbed in a environment where most of the prototypes are under specification and requirements change quickly. In this paper we also present some of the methodology used in order to extract results from this testbed and an insight to what can he done in the future.

 
IP Multicast Dynamic Mapping in Heterogeneous Environments. Diogo Gomes and Rui L Aguiar. In International Symposium on Personal, Indoor and Mobile Radio Communications, pages 1--5, Athens, Greece, sep 2007. IEEE Commun Soc; Natl Tech Univ Athens, IEEE. [ bib | DOI | http ]
Multimedia group communication over IP is an advanced service gaining growing interest from broadcast, fixed and mobile network operators. Next Generation Networks (NGN) will require that IP based multimedia services to be efficiently delivered to groups over heterogeneous networks with QoS. Although being acknowledged as the most efficient way of delivering group communication in packet switched networks, IP multicast still faces some problems associated with QoS that have limited its success in the past. Furthermore the nonexistence of true multicast in wireless technologies has led to an inefficient mapping between the IP and wireless layers. This paper proposes a technique for efficient dynamic mapping of IP Multicast, optimizing its usage for NGN. This technique is evaluated by a prototype on a WiFi environment.

 
NXG01-5: Privacy through Virtual Hording. Diogo Gomes and Rui L Aguiar. In IEEE Globecom 2006, pages 1--6, San Francisco, USA, nov 2006. IEEE. [ bib | DOI | http ]
The wireless digital lifestyle comes to the expense of less privacy and security. This environment is prone to be monitored by rogue users, eager to learn from our lifestyle habits and use them for their own profit. The IP protocol provides very few mechanisms, in order to safeguard user privacy and impair efficient data-mining of user habits. This paper will address an identity architecture that makes use of both data (L2) and network (L3) layer identifiers in order to provide a pseudonimization function, based on virtual hoarding concepts. Our proposal is especially interesting when able to exploit the broadcast and promiscuous nature of wireless communications that usually is regarded as a security concern. A prototype implementation has been developed and tested.

 
QoS Signalling in 4G Scenarios. Susana Sargento, Diogo Gomes, Alfredo Matos, and Rui L Aguiar. In IST Mobile and Wireless Communications Summit, Mykonos, Greece, 2006. [ bib | .pdf ]
II NTRODUCTION Next generation wireless communication systems will handle diverse types of services, across different types of access technologies. This trend, already present in 3G networks and in the current explosion of

 
QoS based multicast architecture for heterogeneous mobile IPv6 environment. Ilka Miloucheva, Hans J Einsiedler, Diogo Gomes, and Karl Jonas. In International Conference on Telecommunications, page 4, Madeira, Portugal, 2006. [ bib ]
With the rapid advances in multimedia content delivery technologies and deployment of user-centric broadband infrastructures, there is an increasing challenge for efficient usage of the Internet resources and enhanced Quality of Service (QoS) support based on multicast. This paper discusses an architectural approach for provision of multicast services for content delivery on demand in the framework of converged fixed / mobile / broadcast infrastructures based on heterogeneous mobile IPv6 environment. Addressed issues include support of multicast transport protocols and mechanisms at access routers for different application requirements (reliable, streaming and real-time) considering asynchronous service requests and caching, QoS management of multicast transport for content delivery, seamless handover and selection of optimal access routers for multicast services. The concepts are based on the current state and possible enhancements of the mobile architecture developed in the European Community (EU) IST project DAIDALOS.

 
Flexible Multicast Service Provision for 4G. Diogo Gomes, Rui L Aguiar, Amardeo Sarma, and Karl Jonas. In WWRF15, Paris, France, 2005. [ bib ]
In a globally connected world filled with rich multimedia services, mobility means making the kind of services utilized independent of the access technology used. The current dependence of Technologies and Services acts as a barrier for the penetration of new markets with new products and services. Broadcast technologies such as DVB and DMB are being deployed over the world. New mobile terminals that carry two interfaces are now able to additionally connect to a broadcast network. Though these broadcast networks provide TV-like services, they lack flexibility and personalization. This paper shows how the Daidalos project has taken up these trends in terms of Mobility and Services Provisioning in a Heterogeneous Network Operator Environment towards a solution that integrates mobility and broadcast.

 
A Next-Generation IPv6 QoS Architecture Integrating Heterogeneous Multicast and Broadcast Networks - Part 1. Diogo Gomes, Emiliano Guainella, Claudio Sansone, Susana Sargento, and Rui L Aguiar. In International Conference on Telecommunications, Cape Town, South Africa, 2005. [ bib ]
Next generation communication systems aim to handle diverse types of services across different types of access technologies in a seamless way. These future mobile networks, usually denoted as 4G networks, will integrate also broadcast networks, such as the TV/Radio networks. This paper presents a future 4G network architecture, based on IPv6, capable of supporting a broad range of multicast services, including multimedia services, like Video Streaming over IP networks, in addition to traditional Internet and Voice services. This first part presents the key architectural elements. A second companion paper presents the signalling mechanisms required for the support of inherent broadcast networks in this architecture.

 
A Next-Generation IPv6 QoS Architecture Integrating Heterogeneous Multicast and Broadcast Networks - Part 2. Diogo Gomes, Emiliano Guainella, Claudio Sansone, Susana Sargento, and Rui L Aguiar. In International Conference on Telecommunications, Cape Town, South Africa, 2005. [ bib ]
Next generation communication systems aim to handle diverse types of services across different types of access technologies in a seamless way. These future mobile networks, usually denoted as 4G networks, will integrate also broadcast networks, such as the TV/Radio networks. This paper presents a future 4G network architecture, based on IPv6, capable of supporting a broad range of multicast services, including multimedia services, like Video Streaming over IP networks, in addition to traditional Internet and Voice services. A architectural key first companion paper presented the elements. This paper proposes signalling scenarios for the set-up of multicast and broadcast sessions with QoS support in intra- and inter-domain scenarios, also addressing the mechanisms for the integration of current Broadcast networks in the architecture, describing a strategy that can be used to support technology.

 
Heterogeneous Signaling Framework for End-to-End QoS Support in Next Generation Networks. Rui Prior, Susana Sargento, Diogo Gomes, and R.L. Aguiar. In Proceedings of the 38th Annual Hawaii International Conference on System Sciences, pages 305c--305c, Big Island, Hawaii, 2005. IEEE. [ bib | DOI | http ]
Next generation wireless communication systems aim to handle diverse types of services across different types of access technologies in a seamless way. This paper proposes a next generation network architecture and evaluates possible associated signaling strategies, focusing in network-level QoS support aspects. The scenarios handled cover terminal-initiated signaling, network controlled signaling, and application-provider controlled signaling. Possible message sequence charts associated with these scenarios are presented and discussed. The paper compares the relative merits of each approach and concludes that the optimum QoS signaling solution depends on the QoS models that will be used, which are directly related to the business models chosen by the operators.

 
End-to-end QoS Architecture for 4G Scenarios. Susana Sargento, Rui Prior, Filipe Sousa, Pedro Gonçalves, Janusz Gozdecki, Diogo Gomes, Emiliano Guainella, Antonio Cuevas, Wojciech Dziunikowski, and Francisco Fontes. In IST Mobile and Wireless Communications Summit, Dresden, Germany, 2005. [ bib | .pdf ]
This paper describes the QoS architecture and the corresponding QoS signalling protocols to be developed inside the IST project Daidalos. We address the main results achieved in terms of the definition of the QoS components and its interfaces, the description of the application and network services, definition of the signalling scenarios for the integration of the QoS signalling with the application signalling and with mobility approaches, and specification of the intra- and inter- domain QoS control approaches. We also describe the QoS management of the system, through the Policy--based Management System, and a Real-time Network Monitoring system able to aid in admission control with the results of active and passive measurements. All the elements, interfaces and functionalities take into account multicast services and inherent broadcast networks.

 
Field Evaluation of a 4G True-IP network. Antonio Cuevas, Pablor Serrano, Carlos Jesus Bernardos, Jose Ignacio Moreno, Jurgen Jaehnert, H W Kim, Jie Zhou, Diogo Gomes, Pedro Gonçalves, and Rui L Aguiar. In IST Mobile and Wireless Communications Summit, Lion, France, jun 2004. [ bib | .pdf ]
This article presents results of an IP-based architecture for heterogeneous environments, covering UMTS-like TD-CDMA wireless access technology, wireless and wired LANs, that has been developed under

 
Integration of Application-level and Network-level Signalling: From UMTS to All-IP. Diogo Gomes, Rui Prior, Susana Sargento, and Rui L Aguiar. In Conferência sobre Redes de Computadores, Leiria, Portugal, 2004. [ bib ]
Next generation wireless communication systems will need to support a wide range of services and applications across different network access technologies. This paper proposes an architecture for the evolution towards next generation All-IP networks and compares it to the traditional UMTS (Universal Mobile Terrestrial System) scenario. The signalling strategies used in both architectures, illustrated with message sequence charts, are analysed with a particular focus on the functional breakdown of tasks across the different network entities and on the interoperation between service and network level signalling required for supporting multimedia communication services with the required QoS. Although simpler than UMTS, the proposed All-IP architecture provides the flexibility to support a great diversity of applications across heterogeneous networks, and is in line with the latest trends in user requirements and expectations, providing new business opportunities to the operators.

 
A transsignaling strategy for QoS support in heterogeneous networks. Diogo Gomes, Pedro Gonçalves, and Rui L Aguiar. In José Neuman De Souza, Petre Dini, and Pascal Lorenz, editors, International Conference on Telecommunications, volume 3124, pages 1114--1121, Fortaleza, Brazil, jan 2004. Springer Berlin / Heidelberg. [ bib | DOI | .pdf ]
The increasing usage of multiple signalling mechanisms, with associated QoS extensions, creates several problems to commercial data networks. New and scalable approaches are required for the network operator to support this diversity. This paper discusses a highly flexible, scalable architecture for processing QoS Admission Control in public networks. The architecture relies on the cooperation of two different entities, an agent and a manager, with fully distributed implementation, and able to perform the required signalling, authorization, and admission control decisions. If required, the agent is capable of interfacing with different signalling mechanisms. Early implementation conclusions are also presented. This architecture is capable of operating with multiple QoS frameworks, with minimal added overhead.

 
A robot with natural interaction capabilities. L.S. Lopes, A.J.S. Teixeira, Mário Rodrigues, Diogo Gomes, J. Girao, C. Teixiera, N. Senica, L Ferreira, and P Soares. In EFTA 2003. 2003 IEEE Conference on Emerging Technologies and Factory Automation. Proceedings (Cat. No.03TH8696), volume 1, pages 605--612, Lisbon, Portugal, nov 2003. IEEE. [ bib | DOI | http ]
This paper describes the architecture and current capabilities of Carl, a prototype of an intelligent service robot, designed having in mind such tasks as serving food in a reception or acting as a host in an organization. The approach that has been .....

 
QoS Control support for heterogeneous networks. Pedro Gonçalves, Diogo Gomes, Victor Marques, and Rui L Aguiar. In Conferência sobre Redes de Computadores, Braganca, Portugal, 2003. [ bib | .pdf ]
Abstract: The increasing utilisation of QoS mechanisms creates many problems to commercial data networks. The multiplicity of requirements posed requires new and scalable approaches from the network operator. This paper discusses a

 
Towards a Personal Robot with Language Interface. Luis Seabra Lopes, António Teixeira, Mário Rodrigues, Diogo Gomes, Claudio Teixeira, L Ferreira, P Soares, João Girão, and Nuno Sénica. In Proc. Eurospeech'2003, pages 2205--2208, Geneva, Switzerland, jan 2003. [ bib | http ]
The development of robots capable of accepting instructions in terms of familiar concepts to the user is still a challenge. For these robots to emerge it's essential the development of natural language interfaces, since this is regarded as the only interface acceptable for a machine which expected to have a high level of interactivity with Man. Our group has been involved for several years in the development of a mobile intelligent robot, named Carl, designed having in mind such tasks as serving food in a reception or acting as a host in an organization. The approach that has been followed in the design of Carl is based on an explicit concern with the integration of the major dimensions of intelligence, namely Communication, Action, Reasoning and Learning. This paper focuses on the multi-modal human-robot language communication capabilities of Carl, since these have been significantly improved during the last year.

 
A friendly and flexible human-robot interface for CARL. Luis Seabra Lopes, António Teixeira, Diogo Gomes, Claudio Teixeira, and João Girão. In Robotica 2003, Lisbon, Portugal, 2003. [ bib | .pdf ]
This paper describes the architecture and current capabilities of Carl, a prototype of an intelligent service robot, designed having in mind such tasks as serving food in a reception or acting as a host in an organization. The approach that has been followed in the design of Carl is based on an explicit concern with the integration of the major dimensions of intelligence, namely Communication, Action, Reasoning and Learning. The paper focuses on the multi-modal human-robot communication capabilities of Carl, since these have been significantly improved during the last year.

Participations in Projects

  • 5GinFIRE - Evolving FIRE into a 5G-Oriented experimental playground for vertical industries
  • Apollo - M2M Platform, a project funded by QREN 2011/021580
  • C-Cast - Evolution of mobile multimedia multicasting to exploit the increasing integration of mobile devices with our everyday physical world and environment, an EU Framework Programme 7 Project, INFSO-ICT-216462
  • C-Mobile - Advanced MBMS For the future mobile world, an EU Framework Programme 6 Project, IST-2004-027423
  • Akogrimo - Access to Knowledge through the Grid in a mobile World, an EU Framework Programme 6 Integrated Project, IST-2002-4293
  • Daidalos - Designing Advanced network Interfaces for the Delivery and Administration of Location independent, Optimised personal Services, an EU Framework Programme 6 Integrated Project, IST-2002-506997
  • Moby Dick - Mobility and Differentiated Services in a Future IP Network, an Eu Framework Programme 5, IST-2000-25394
  • CARL - Communication, Action, Reasoning and Learning in Robotics, funded by program PRAXIS XXI, reference PRAXIS/P/EEI/12121/1998