An Aspect-Oriented Approach for Supporting Autonomic Reconfiguration of Software Architecture

The increasing complexity of current software systems is encouraging the development of self-managed software architectures, i.e. systems capable of reconfiguring their structure at runtime to fulfil a set of goals. Several approaches have covered different aspects of their development, but some issues remain open, such as the maintainability or the scalability of self-management subsystems. Centralized approaches, like self-adaptive architectures, offer good maintenance properties but do not scale well for large systems. On the contrary, decentralized approaches, like self-organising architectures, offer good scalability but are not maintainable: reconfiguration specifications are spread and often tangled with functional specifications. In order to address these issues, this paper presents an aspect-oriented autonomic reconfiguration approach where: (1) each subsystem is provided with self-management properties so it can evolve itself and the components that it is composed of; (2) self-management concerns are isolated and encapsulated into aspects, thus improving its reuse and maintenance. Povzetek: Predstavljen je pristop s samo-preoblikovanjem programske arhitekture.

Multi Domain-Specific Modeling of the Security Concerns of Service-Oriented Architectures

Service-Oriented Architectures (SOA), and Web Services (WS), the technology generally used to implement them, achieve the integration of heterogeneous technologies, providing interoperability, and yielding the reutilization of pre-existent systems. Model-driven development methodologies provide inherent benefits such as increased productivity, greater reuse, and better maintainability, to name a few. Efforts on achieving model-driven development of SOAs already exist, but there is currently no standard solution that addresses non-functional aspects of these services as well. This paper presents an approach to integrate these non-functional aspects in the development of web services, with an emphasis on security.

LTE as the future railway communication system: benefits and challenges

In this paper the main challenges associated with the migration process towards LTE, will be assessed. These challenges comprise, among others, the next key topics: Reliability, Availability Maintainability and Safety (RAMS) requirements, end to end Quality of Service (QoS) requirements, system performance in high speed scenarios, communication system deployment strategy, and system backward compatibility as well as the future system features for delivering railway services. The practical evaluation of the LTE system capabilities and performance in High Speed Railway (HSR) scenarios, require the development of an LTE demonstrator and an LTE system level simulator. Under this scope, the authors have developed an RF LTE demonstrator, as well as an LTE system level simulator, that will provide valuable information for the assessing of LTE performance and suitability in real HSR scenarios. This work is being developed under the framework of a research project to evaluate the feasibility of LTE to become the new railway communication system. The companies and universities involved in this project are: Technical University of Madrid (UPM), Alcatel Lucent Spain, ADIF (Spanish Railway Infrastructure Manager), Metro de Madrid, AT4 Wireless, the University of A Coruña (UDC) and University of Málaga (UMA).