Diogo Gomes

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.

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.

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.

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.

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]

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

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

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.

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.

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.

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.

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.

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.

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.

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.

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.

This paper analyzes the applicability of context-based multicast content distribution (CBMCD) on the example of realistic push- and videobased 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.

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.

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 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.

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.

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.

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.

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.

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

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.

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.

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.

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.

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.

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

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.

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.

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 .....

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

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.

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.