Signaling System 7 (SS7) defines the network architecture, configuration and message transport protocol for Public Telephone Networks (PTNs). SS7 was originally designed for a closed telecommunications community, and therefore possesses limited authentication facilities. Deregulation coupled with PTN convergence with the Internet and wireless networks significantly increase vulnerabilities, ena...

To allow for wireless communications among a specific geographic area, base stations of communication network must be deployed to allow sufficient radio coverage to every mobile users. The base stations, successively, must be linked to a central hub called the MSC (mobile switching centre). The mobile switching centre allow connectivity among the PSTN (public switched telephone network) and the...

WORLD TELEPHONE SPEECH APPLICATIONS Pieter Vermeulen, Etienne Barnard, Yonghong Yan, Mark Fanty and Ronald Coley Center for Spoken Language Understanding, Oregon Graduate Institute of Science and Technology 20000 N.W. Walker Road, P.O. Box 91000, Portland, OR 97291-1000, USA Tel: +1 503-6901484, E-mail: [email protected] ABSTRACT We compare a standard HMM based and a neural network based appro...

This paper considers the competitive issues raised by the continuing evolution of public switched telephone network development toward an open data network. Adopting a platform hierarchy set forth by the National Research Council, the paper agrees that some higher level services may indeed reduce traditional telephone company revenues, but argues that it would be counterproductive for regulator...

TELEPHONE SPEECH RECOGNITION SYSTEM Johan Schalkwyk, Pieter Vermeulen, Mark Fanty and Ronald Coley Center for Spoken Language Understanding, Oregon Graduate Institute of Science and Technology 20000 N.W. Walker Road, P.O. Box 91000, Portland, OR 97291-1000, USA Tel: +1 503-6901318, E-mail: [email protected] ABSTRACT An embedded implementation of a hybrid neural-network based telephone speech r...

Voice over Internet Protocol (VoIP) is being widely deployed to offer users low-cost alternatives for long-distance and international telephone calls. However, for users who are accustomed to the high-quality sound offered by traditional Public Switched Telephone Network (PSTN) service, VoIP voice quality often pales in comparison. Voice quality in VoIP networks widely varies as a result of sev...

Recently, it has been found that the degree distribution of a user network has a significant effect on the traffic carried by a telephone network. In this paper, we investigate the effect of user clustering on the telephone traffic based on computer simulations. Both uniform and scale-free user networks have been considered. In a uniform user network, it has been found that the carried traffic ...

In this paper, we present a large vocabulary , speaker independent speech recognition sys-tem(KT-STOCK) and describe its performance over the telephone network. KT-STOCK is a stock information retrieval system with which we can obtain the current price of a stock by saying a stock name among 710 stock names listed on the Korea stock exchange. The system is an HMM(hidden Markov model)-based isol...

Preface This dissertation is the result of my own work and includes nothing which is the outcome of work done in collaboration except where specifically indicated in the text. I hereby declare that my thesis does not exceed the limit of length prescribed in the Special Regulations of the M. Phil. examination for which I am a candidate. The length of my thesis is 14980 words. Acknowledgements I ...

The paper discusses the application of mobile agents in the management of mobile telephone (cellular) networks. We propose the use of mobile agents for collecting subscriber information, such as location area identifier and cell identifier. By using a subscriber profile containing these data the signaling messages caused by location update could be reduced. We also propose a method to improve t...