4,853 research outputs found
Ensuring interoperability between network elements in next generation networks
Next Generation Networks (NGNs), based on the Internet Protocol (IP), implement
several services such as IP-based telephony and are beginning to replace the classic telephony
systems. Due to the development and implementation of new powerful services
these systems are becoming increasingly complex.
Implementing these new services (typically software-based network elements) is often
accompanied by unexpected and erratic behaviours which can manifest as interoperability
problems. The reason for this caused by insufficient testing at the developing
companies. The testing of such products is by nature a costly and time-consuming
exercise and therefore cut down to what is considered the maximum acceptable level.
Ensuring the interoperability between network elements is a known challenge. However,
there exists no concept of which testing methods should be utilised to achieve an
acceptable level of quality. The objective of this thesis was to improve the interoperability
between network elements in NGNs by creating a testing scheme comprising of
three diverse testing methods: conformance testing, interoperability testing and posthoc
analysis.
In the first project a novel conformance testing methodology for developing sets of conformance
test cases for service specifications in NGNs was proposed. This methodology significantly improves the chance of interoperability and provides a considerable enhancement to the currently used interoperability tests. It was evaluated by successfully
applying it to the Presence Service.
The second report proposed a post-hoc methodology which enables the identification
of the ultimate causes for interoperability problems in a NGN in daily operation. The
new methods were implemented in the tool IMPACT (IP-Based Multi Protocol Posthoc
Analyzer and Conformance Tester), which stores all exchanged messages between
network elements in a database. Using SQL queries, the causes for errors can be found
efficiently.
Overall the presented testing scheme improves significantly the chance that network
elements interoperate successfully by providing new methods. Beyond that, the quality
of the software product is raised by mapping these methods to phases in a process model
and providing well defined steps on which test method is the best suited at a certain
stage
OSI-compatible protocols for mobile-satellite communications: The AMSS experience
The protocol structure of the international aeronautical mobile satellite service (AMSS) is reviewed with emphasis on those aspects of protocol performance, validation, and conformance which are peculiar to mobile services. This is in part an analysis of what can be learned from the AMSS experience with protocols which is relevant to the design of other mobile satellite data networks, e.g., land mobile
A collaborative platform for integrating and optimising Computational Fluid Dynamics analysis requests
A Virtual Integration Platform (VIP) is described which provides support for the integration of Computer-Aided Design (CAD) and Computational Fluid Dynamics (CFD) analysis tools into an environment that supports the use of these tools in a distributed collaborative manner. The VIP has evolved through previous EU research conducted within the VRShips-ROPAX 2000 (VRShips) project and the current version discussed here was developed predominantly within the VIRTUE project but also within the SAFEDOR project. The VIP is described with respect to the support it provides to designers and analysts in coordinating and optimising CFD analysis requests. Two case studies are provided that illustrate the application of the VIP within HSVA: the use of a panel code for the evaluation of geometry variations in order to improve propeller efficiency; and, the use of a dedicated maritime RANS code (FreSCo) to improve the wake distribution for the VIRTUE tanker. A discussion is included detailing the background, application and results from the use of the VIP within these two case studies as well as how the platform was of benefit during the development and a consideration of how it can benefit HSVA in the future
Cyber-Virtual Systems: Simulation, Validation & Visualization
We describe our ongoing work and view on simulation, validation and
visualization of cyber-physical systems in industrial automation during
development, operation and maintenance. System models may represent an existing
physical part - for example an existing robot installation - and a software
simulated part - for example a possible future extension. We call such systems
cyber-virtual systems.
In this paper, we present the existing VITELab infrastructure for
visualization tasks in industrial automation. The new methodology for
simulation and validation motivated in this paper integrates this
infrastructure. We are targeting scenarios, where industrial sites which may be
in remote locations are modeled and visualized from different sites anywhere in
the world.
Complementing the visualization work, here, we are also concentrating on
software modeling challenges related to cyber-virtual systems and simulation,
testing, validation and verification techniques for them. Software models of
industrial sites require behavioural models of the components of the industrial
sites such as models for tools, robots, workpieces and other machinery as well
as communication and sensor facilities. Furthermore, collaboration between
sites is an important goal of our work.Comment: Preprint, 9th International Conference on Evaluation of Novel
Approaches to Software Engineering (ENASE 2014
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