Calypso Service Architecture for Broadband Networks

The Calypso project aims at developing an extremely flexible control and service architecture for ATM-based broadband networks. This architecture provides various alternatives to distribute the network and service control functions among clients, servers and different network nodes. This means that a control or service function can reside not only in a network node, but in the customer's workstation or in the service provider's dedicated server. Instead of the traditional ATM or IN signalling, the Calypso architecture uses the TCP/IP protocol suite for the management and control of the network and services. The management, control and user data is transferred by means of IP switching. In addition to IP switching, the architecture will support endto -end native ATM streams with guaranteed Quality of Service. In this paper we compare the Calypso architecture with the traditional B-ISDN and IN architectures. We focus on describing the Java-based Service Execution Environment that provides..

The VITI program: Final Report

In this report we present our findings and results from the VITI program in 2000. The focus of the research work undertaken by VITI has been to provide electronic meeting environments that are easy to use and afford as natural a collaboration experience as possible. This final report is structured into three parts. Part one concerns the VITI infrastructure and consists of two sections. The first section describes the process of establishing the infrastructure, concentrating on how the work was done. The second section presents the actual infrastructure that is in place today, concentrating on what has been put in place. Part two examines the use the VITI infrastructure has been put to, giving examples of activities it has supported and discussing strengths and weaknesses that have emerged through this use. Finally part three considers the future of distributed electronic meeting environments. It is recommended that the report be read in the order in which it is presented. However, each section has been written as a standalone document and can be read independently of the others

Real-life performance of protocol combinations for wireless sensor networks

Wireless sensor networks today are used for many and diverse applications like nature monitoring, or process and wireless building automation. However, due to the limited access to large testbeds and the lack of benchmarking standards, the real-life evaluation of network protocols and their combinations remains mostly unaddressed in current literature. To shed further light upon this matter, this paper presents a thorough experimental performance analysis of six protocol combinations for TinyOS. During these protocol assessments, our research showed that the real-life performance often differs substantially from the expectations. Moreover, we found that combining protocols is far from trivial, as individual network protocols may perform very different in combination with other protocols. The results of our research emphasize the necessity of a flexible generic benchmarking framework, powerful enough to evaluate and compare network protocols and their combinations in different use cases