Modernizing National Numbering Plan on NGN Platform - Hungarian Case Study

The intensive technological development of the last years brought the overall acceptance of an IP based network and services vision based on the NGN. The realization of the NGN vision, the decision on the migration to NGN sets regulatory tasks, especially in the area of numbering and addressing. The utilization of the opportunities provided by the NGN platform requires the use of IP addresses and names in the core network, the role of the E.164 numbers is taken over by IP addresses. However in case of voice services the identification of end-user access points will remain by the use of E.164 numbers. Migration to NGN doesn't require directly the change of the subscribers' phone number; however the NGN enables among others the implementation of national number portability for fixed telephone service. The opportunities can be realized by using uniform domestic number length and dialling method, practically closed numbering. The introduction of a 9-digit uniform, closed domestic numbering provides a consistent solution for the deficiencies of the present Hungarian numbering plan, too. Recently it can be reached in single step so that the present 9-digit domestic numbers and the short codes remain unchanged, the 8-digit domestic numbers are completed to 9-digit by the insertion of an appropriate digit, as well as the present and new numbering schemes can be in operation simultaneously. --

Component-based situational methods

International audienceThe work presented in this paper is related to the area of Situational Method Engineering (SME) which focuses on project-specific method construction. We propose a faceted framework to understand and classify issues in system development SME. The framework identifies four different but complementary viewpoints. Each view allows us to capture a particular aspect of situational methods. Inter-relationships between these views show how they influence each other. In order to study, understand and classify a particular view of SME in its diversity, we associate a set of facets with each view. As a facet allows an in-depth description of one specific aspect of SME, the views show the variety and diversity of these aspects

Total Haskell is Reasonable Coq

We would like to use the Coq proof assistant to mechanically verify properties of Haskell programs. To that end, we present a tool, named hs-to-coq, that translates total Haskell programs into Coq programs via a shallow embedding. We apply our tool in three case studies -- a lawful Monad instance, "Hutton's razor", and an existing data structure library -- and prove their correctness. These examples show that this approach is viable: both that hs-to-coq applies to existing Haskell code, and that the output it produces is amenable to verification.Comment: 13 pages plus references. Published at CPP'18, In Proceedings of 7th ACM SIGPLAN International Conference on Certified Programs and Proofs (CPP'18). ACM, New York, NY, USA, 201

Evaluating Model Testing and Model Checking for Finding Requirements Violations in Simulink Models

Matlab/Simulink is a development and simulation language that is widely used by the Cyber-Physical System (CPS) industry to model dynamical systems. There are two mainstream approaches to verify CPS Simulink models: model testing that attempts to identify failures in models by executing them for a number of sampled test inputs, and model checking that attempts to exhaustively check the correctness of models against some given formal properties. In this paper, we present an industrial Simulink model benchmark, provide a categorization of different model types in the benchmark, describe the recurring logical patterns in the model requirements, and discuss the results of applying model checking and model testing approaches to identify requirements violations in the benchmarked models. Based on the results, we discuss the strengths and weaknesses of model testing and model checking. Our results further suggest that model checking and model testing are complementary and by combining them, we can significantly enhance the capabilities of each of these approaches individually. We conclude by providing guidelines as to how the two approaches can be best applied together.Comment: 10 pages + 2 page reference

VoIP under the EU regulatory framework : preventing foreclosure?

In June 2004, the European Commission (EC) issued an "Information and Consultation Document" (European Commission 2004) that discussed how the Regulatory Framework of the European Union (EU) should be adapted to accommodate Voice over IP (VoIP) and invited relevant parties to comment on the Consultation Document. In our study, we use the responses of the different market parties to identify how incumbents seek to foreclose the market for VoIP telephony. From these responses we conclude that foreclosure is not only attempted by setting high prices for the use of infrastructure, but also by the strategic choice of infrastructure technology, which raises the cost of entry. We label the latter form of foreclosure "technological foreclosure" – as opposed to "market foreclosure". A simple modeling exercise shows that regulators seeking to avoid market foreclosure might trigger technological foreclosure. We argue that this has happened with the unbundling of the local loop in the EU, and that it might happen again with the transition to VoIP. We conclude that the current rights and obligations assigned to telecom companies effectively protect incumbents from competition by VoIP entrants. Moreover, the inaction of regulatory authorities when it comes to numbering and communication protocols is advantageous for incumbents and might obstruct the provision of new services in the future