The work addresses the use of model-based techniques for diagnosing telecommunication networks. The aim is to design a system for help in supervision of the main packet switching French telecommunication network, in s...
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The work addresses the use of model-based techniques for diagnosing telecommunication networks. The aim is to design a system for help in supervision of the main packet switching French telecommunication network, in such a way as to be both generic and efficient, i.e. able to support technological evolution and to meet realtime constraints. The network is made up of about ten technical centers and about three hundred switches, and a lot of depending stations devoted to the data transmission. It is hierarchically structured. The architecture is made up modeling, simulation, discrimination, and recognition modules. A prototype of the system has been developed, which implements a modelling module as well as a simulation module. It has been tested on data files supplied by CNET/France-Telecom. The discrimination module is currently under development. A comparison between the results obtained by the model-based approach and the expert system approach which is currently in use at the supervision center has been done and gives satisfying results.
Describes some of the more important aspects of real-time networks, and shows how such networks can be used to control and analyse the temporal properties of computer-based systems. At the heart of the approach is the...
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Describes some of the more important aspects of real-time networks, and shows how such networks can be used to control and analyse the temporal properties of computer-based systems. At the heart of the approach is the characterisation of information flows in terms of a small set of well-defined protocols, and the reflection of these protocols within the functional, design, implementation and execution models for a system. This provides a well-defined and traceable path from functional description through to execution, so allowing temporal requirements within applications to be expressed in a form such that they can be guaranteed (by analysis) to be met within the corresponding network solutions. The paper begins with a brief discussion of network models of computation, before moving on to the communication dynamics which lie at the heart of this network approach. Traceability and interface issues are then considered, followed by aspects of timing analysis. The paper concludes with a small example to illustrate the more important features of the approach.< >
A review of the design of a radio communication system utilizing all propagation mechanisms in the frequency range 2-200 MHz is conducted. The design of control algorithms utilizing embedded real-time channel evaluati...
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ISBN:
(纸本)0852966164
A review of the design of a radio communication system utilizing all propagation mechanisms in the frequency range 2-200 MHz is conducted. The design of control algorithms utilizing embedded real-time channel evaluation (RTCE) is of critical importance since the success of the system relies on its ability to adapt to the prevailing propagation mechanisms. A review is also made on propagation simulation methods implemented to aid the systemdevelopment, including a model of the tropospheric reflection mode.
RDD-100 is a systems engineering tool which has its roots in the manual techniques employed on the USA's ballistic missile defence projects in the period 1975-1985. This methodology was very much focused on predic...
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RDD-100 is a systems engineering tool which has its roots in the manual techniques employed on the USA's ballistic missile defence projects in the period 1975-1985. This methodology was very much focused on predicting and then guaranteeing a system's overall response time in reacting to in-coming threats. RDD-100 adopts the view that systems development is best achieved by incrementally developing a system model that will persist over the lifecycle and be shared and managed by the people involved. RDD-100 provides a unique capability of modelling system behaviour and investigating the dynamic aspects of this behaviour. It enables system architectures to be represented and provides valuable information which can be used as the basis for trade-off analysis. RDD-100 also supports system requirements extraction, traceability from requirements to system specification and design, and the ability to generate major reports directly from the RDD-100 database. Above all, RDD-100 allows a single model to be built that can persist over the lifecycle and be shared and managed by the people involved.< >
Summarises recent research in real-time knowledge-based methods and techniques conducted by the Defence Research Agency and Cambridge Consultants. This paper also reports on the development of a large-scale prototype ...
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Summarises recent research in real-time knowledge-based methods and techniques conducted by the Defence Research Agency and Cambridge Consultants. This paper also reports on the development of a large-scale prototype that demonstrates the effectiveness of this research. The scope of the research concerns the development of a knowledge acquisition method for real-time applications, the development of tools that compile the knowledge produced by a knowledge engineering toolset for execution in the Muse real-time KBS toolkit and experimental extensions to Muse to support concurrent real-time execution, referred to as D-Muse. Prior work has demonstrated that knowledge-based techniques provide useful functionality, but in order to meet real-time decision support requirements, these areas needed to be addressed. A prototype is being constructed to demonstrate the effectiveness of the research. It concerns a real-time decision support system to enhance the performance of a helicopter aircrew engaged in a naval mission to search and identify contacts in coastal water.
The National Grid Company (NGC) has a national scheme to provide cable system monitors (CSMs) installed in its Area Control Centres. The CSMs will provide on-line continuous and overload thermal ratings of cables base...
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ISBN:
(纸本)0852965923
The National Grid Company (NGC) has a national scheme to provide cable system monitors (CSMs) installed in its Area Control Centres. The CSMs will provide on-line continuous and overload thermal ratings of cables based on system measurements and real-time thermal modelling, and will enable the control engineers to assess the present security of the system and plan the operation of the system for the next day or possibly the following week. The CSM will also hold archive data for retrieval and subsequent analysis. A transient thermal cable rating method is employed in the CSM which can be applied to various cable system designs. The method is a development of that described in Electra No 87 and recommended in IEC853-2. Software has been developed for cable design calculations on an off-line system;a derivative of this software has been provided in a form suitable for inclusion in a real-timesystem, a SCADA system supplied by a third party. Most combinations of cable installations on one circuit can be monitored by the CSMs including cable in air, cables in tunnels, and cables buried normally, in troughs, in ducts, or with water cooling. Approximate methods for dealing with partially dried out soil and dual thermal resistivity installations can be applied to the CSM. Mutual heating effects between neighbouring circuits are included. New rating and measurement techniques will be introduced to the CSM as they become available. One aim of the CSM is to allow new cable circuits to be designed with their thermal characteristics matched to the operational and security requirements of the transmission network.
The authors look at RTSASD (realtime structured analysis and structured design) which is used in software engineering for systemdevelopment. They concentrate on object-oriented analysis and why it is the preferred m...
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The authors look at RTSASD (realtime structured analysis and structured design) which is used in software engineering for systemdevelopment. They concentrate on object-oriented analysis and why it is the preferred method in the telecommunications industry.< >
Over the past few years there has been an increased awareness of the need for methods to cover the complete software development life-cycle. There are a large number of methods available. No one method covers the comp...
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Over the past few years there has been an increased awareness of the need for methods to cover the complete software development life-cycle. There are a large number of methods available. No one method covers the complete development process. The paper gives a brief sketch of five of the most widely mentioned methods: CORE, Yourdon, JSD, SSADM and MASCOT3. It then compares them from the points of view of techniques and representations, method and life-cycle coverage. Finally some possible combinations of methods which give good life-cycle coverage are suggested and related to the use of Ada as the preferred programming language.< >
This paper concerns the application of rule and knowledge based techniques to the control and optimisation of industrial processes. It is based on work initiated by Blue Circle plc for the optimisation of the control ...
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This paper concerns the application of rule and knowledge based techniques to the control and optimisation of industrial processes. It is based on work initiated by Blue Circle plc for the optimisation of the control of cement kilns. This work has resulted in the development of a commercial product, known as LINKman, which has been installed successfully in twenty three plants worldwide where it achieves substantial savings in fuel and improvements in quality. This paper looks at the techniques and discusses some of the practical issues involved in their application.< >
Designing software to control real-time, reactive embedded applications is non-trivial. And as the complexity of such systems increases, the present industrial practice for their development gives cause for concern, e...
Designing software to control real-time, reactive embedded applications is non-trivial. And as the complexity of such systems increases, the present industrial practice for their development gives cause for concern, especially, if they are to be used in safety-critical applications. In order for the design of these systems to be optimised, it is necessary to take into account the interdependence of the hardware and software. Thus, the system needs to be assessed at all stages of the development life-cycle in order to minimise the potential for errors. This has resulted in the development of a wide range of techniques which aim to support the analysis and design of both systems and their associated software. These vary from those with sound mathematical basis (formal methods) to structured methodologies. The latter while useful, do not provide a satisfactory and comprehensive solution. The former, on the other hand, are recognised as the most likely solution to the problem, but insufficient expertise and a lack of tool support have limited their practical deployment to highly specialised applications.
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