Abstract
This paper presents the Inter-Module Communication (IMC) protocol, a message-oriented protocol designed and implemented in the Underwater Systems and Technology Laboratory (LSTS) to build interconnected systems of vehicles, sensors and human operators that are able to pursue common goals cooperatively by exchanging real-time information about the environment and updated objectives. IMC abstracts hardware and communication heterogeniety by providing a shared set of messages that can be serialized and transferred over different means. The described protocol contrasts with other existing application level protocols by not imposing or assuming a specific software architecture for client applications. Native support can be automatically generated for different programming languages and/or computer architectures resulting in optimized code which can be used both for networked nodes and also for inter-process and inter-thread communication. The protocol has already been tested throughout various experiments led by LSTS where it has taken care of communications between vehicles, sensors and operator consoles. We are now developing the protocol in the direction of having multi-vehicle cooperation using live data from environmental sensors and mixed-initiative user interaction.

Abstract
This paper further develops an architecture and design elements for a resource management and a signalling system to support the construction and maintenance of a mid-long term hybrid multicast tree for multimedia distribution services in a QoS guaranteed way, over multiple IP domains. The system called E-cast is composed of an overlay part - in inter-domain and possible IP level multicast in intra-domain. Each E-cast tree is associated with a given QoS class and is composed of unicast pipes established through Service Level Specification negotiations between the domain managers. The paper continues a previous work, by proposing an inter-domain signalling system to support the multicast management and control operations and then defining the resource management for tree construction and adjustment procedures in order to assure the required static and dynamic properties of the tree.

Abstract
Network operators have been reluctant to deploy IP multicast services mainly due to the lack of native control rover multicast groups. This lack of control does not only prevent operators from generating revenue from multicast-based services but also hinders regular network management. In this work we identified the network elements where admission control should be enforced for multicast session spawning over heterogeneous access networks. The architecture proposed uses existing AAA functionality to perform user identification and multicast session admission control. This control is made at the network layer with no protocol modifications. Three access networks were considered: xDSL, WiMAX and UMTS.

Abstract
Technological evolution is leading telecommunications toward all-IP scenarios, where multiple services are transported as IP packets. Among these services is the broadcast of video. A possible mechanism for broadcasting multiple video channels over IP is to use IP multicast, and let each client decide about the reception of a channel. The secure IP multicast specified by the IETF MSEC working group is a candidate solution for securing these broadcast services. In this paper we propose a new solution for supporting the broadcast of multiple video channels which can be accessed only by authorized users; besides, when a video channel is not visualized in the last mile its transmission is temporarily suspended, so that the cable can be used for other services such as standard Internet access.

Abstract
Learning objects are not a new concept, being currently produced either according to existent specifications, or in an ad hoc way. However, a system that can easily classify them for automatic storage is still missing In this article we propose a repository of learning objects which is capable of automatic classification and categorization based on a semantic organization. The classification is based on a text extraction mechanism which then uses text mining methods. We present a methodology for the initial clustering of objects, and a technique for maintaining the organization with continuous arrival of new objects.

Abstract
The general available tools for analyzing interactions in online discussion forums appear to be insufficient to characterize groups of medium/large dimensions, as they are limited to provide general information of participation, access statistics and message posting. Our research contributes for analyzing and characterizing asynchronous online interactions applying the Social Network Analysis methodology, by providing e-learning platforms with an interactive graph - the iGraph - that illustrates, and analyses, students' interactions. In a graphical interface embedded in an open source learning management system we combine real-time graphs and numerical indicator to provide the educator with a more thorough understanding of relations between course participants. Preliminary results indicate that the iGraph enables an insightful characterization of the interactions between actors and their participations in discussion forums.