Schemes for fault identification in communication networks

A single fault in a large communication network may result in a large number of fault indications (alarms) making the isolation of the primary source of failure a difficult task. The problem becomes worse in cases of multiple faults. In this paper we present an approach for modelling the problem of fault diagnosis. We propose a graph based network model that takes into account the dependencies among the different objects in the telecommunication environment and a novel approach to estimate the domain of an alarm. Based on that model, we design an algorithm for fault diagnosis and analyze its performance with respect to the accuracy of the fault hypotheses it provides. We also propose and analyze a fault diagnosis algorithm suitable for systems for which an independent failure assumption is valid. Finally, we examine the importance of the information of dependency between objects for the fault diagnosis process     

Channel assignment schemes for cellular mobile telecommunication systems: A comprehensive survey

This article provides a detailed discussion of wireless resource and channel allocation schemes. The authors provide a survey of a large number of published papers in the area of fixed, dynamic, and hybrid allocation schemes and compare their trade-offs in terms of complexity and performance. We also investigate these channel allocation schemes based on other factors such as distributed⁄centralized control and adaptability to traffic conditions. Moreover, we provide a detailed discussion on reuse partitioning schemes, the effect of handoffs, and prioritization schemes. Finally, we discuss other important issues in resource allocation such as overlay cells, frequency planning, and power control.     

Distributed fault identification in telecommunication networks

Telecommunications networks are often managed by a large number of management centers, each responsible for a logically autonomous part of the network. This could be a small subnetwork such as an Ethernet, a Token Ring or an FDDI ring, or a large subnetwork comprising many smaller networks. In response to a single fault in a telecommunications network, many network elements may raise alarms, which are typically reported only to the subarea management center that contains the network element raising the alarm. As a result, a particular management center has a partial view of the status of the network. Management Centers must therefore cooperate in order to correctly infer the real cause of the failure. The algorithms proposed in this paper outline the way these management centers could collaborate in correlating alarms and identifying faults.Work done while the author was with the IBM T. J. Watson Research Center, New York.Work done while the author was with the IBM T. J. Watson Research, Center, New York.Work done during the author's internship at the IBM T. J. Watson Research Center, New York, Summer 93.