Compositional Analysis of Real-Time Embedded Systems

This tutorial is concerned with various aspects of component-based design and compositional analysis of real-time embedded systems. It will first give an overview of component-based frameworks and their underlying principles. It will then go in-depth into abstraction methods for real-time components and techniques for computing their optimal interfaces, for both systems implemented on uniprocessor and multiprocessor platforms, as well as extensions to multi-mode systems. Besides theoretical aspects, the tutorial will also present an implementation of the compositional analysis framework on Xen virtualization and a demonstration of the CARTS toolset with several examples seeing the techniques in action. It will also include two case studies highlighting the utility of the framework, including the ARINC-653 avionics software and a smart-phone application. We will conclude the tutorial with a number of open challenges and research opportunities in this domain

An Empirical Study of User Support Tools in Open Source Software

End users’ positive response is essential for the success of any software. This is true for both commercial and Open Source Software (OSS). OSS is popular not only because of its availability, which is usually free but due to the user support it provides, generally through public platforms. The study model of this research establishes a relationship between OSS user support and available support tools. To conduct this research, we used a dataset of 100 OSS projects in different categories and examined five user support tools provided by different OSS projects. The results show that project trackers, user mailing lists, and updated versions have a significant role in gaining user support. However, we were unable to find a significant association between user support and documentation, as well as between user support and the troubleshooting guidelines provided by OSS projects

IP Mobile Multicast over Next Generation Satellite Networks. Design and Evaluation of a Seamless Mobility Framework for IP Multicast Communications over a Multi-beam Geostationary Satellite Network

The inherent broadcast nature of satellites, their global coverage and direct access to a large number of subscribers give satellites unrivalled advantages in supporting IP multicast applications. A new generation of satellite systems that support regenerative on-board processors and multiple spot beam technology have opened new possibilities of implementing IP multicast communication over satellites. These new features enable satellites to make efficient use of their allocated bandwidth resources and provide cost effective network services but equally, create new challenges for mobile satellite terminals. IP mobility support in general and IP mobile multicast support in particular on mobile satellite terminals like the ones mounted on continental flights, maritime vessels, etc., still remain big challenges that have received very little attention from the research community. Up till now, there are no proposed mechanisms to support IP multicast for mobile receivers/sources in multi-beam satellite networks in open literature. This study explores the suitability of IP multicast mobility support schemes defined for terrestrial networks in a satellite environment and proposes novel schemes based on the concepts of Home and Remote subscription-based approaches, multiple interface and PMIPv6 protocol. Detailed analysis and comparison of results obtained from the proposed schemes, Mobile IP (MIP) Home and Remote subscription-based approaches (for terrestrial networks) when implemented on a reference multi-beam satellite network are presented. From these results, the proposed schemes outperform the MIP Home and Remote subscription-based approaches in terms of gateway handover latency, number of multicast packets lost and signalling cost over the satellite air interface