ISSN:1074-5351    

DOI:10.1002/dac.4500070202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractTelecommunication services are traditionally described from the terminal viewpoint, including the user interaction with the service, as well as the specific terminal characteristics to the network that it is meant for. Also traditionally the instance of the telecommunication service was a call and a connection as a one‐to‐one couple.Nowadays networks with powerful multimedia/multiconnection/multiparty capabilities require that a telecommunication service should not be described any more as a conglomerate, but by its main service elements, which in turn are supported by other service elements, so that a service may be built up by building blocks in a levelled model.The criteria to be considered to find these elements are the user viewpoint, the information coding (or terminal) viewpoint and the network access viewpoint. This leads to the telecommunication service, party, party edge, user service module and abstract service module as pure user‐dependent service elements, the service module for the terminal aspect, and the access connection element for transfer of the information over the network.All these basic service elements are ordered in a levelled structure called a multilevel framework. Each level or co‐level represents a service element type which may be instantiated as a service object, and which is described statically by a table of attributes. Attributes for each level are listed and clarified.An example describing a well‐known service is given to illustrate the use of the framework.The views expressed in this document have been developed by the RACE 2044 MAGIC.RACE: Research into Advanced Communication Technologies for Europe. MAGIC: Multi‐service Applications Governing Integrated Control.The concepts presented are related to Release 2 and 3 for BISDN as defin

ISSN:1074-5351    

DOI:10.1002/dac.4500070203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractThe former CCITT has defined a methodology, consisting of three stages, to evolve from a set of service descriptions to a protocol definition that supports these services. In the first stage, the service is described from a user's viewpoint. A part of this first stage consists of the descriptions of the dynamic behaviour of the service. The introduction of this paper elaborates on the interpretation of the ‘user's viewpoint’ of dynamic service descriptions. In the subsequent sections we introduce an object‐oriented approach to define a framework for the dynamic service descriptions. The flexible definition of services is facilitated by decomposing the service into a standard set of building blocks, referred to as service objects. A service object is the smallest service element that a user can independently reference and manipulate. By modelling in terms of service objects, we avoid the presumption that the total service consists of a specific number of parties or connections. The definition of a service mainly consists of imposing additional semantic rules on the way service objects can be manipulated within the context of that service. The complete system will thus consist of a servicespecific part and a generic part, i.e. a part which is common to all services. An overview of the system configuration and the behaviour of the generic part is illustrated by SDL Descriptions. Finally, we illustrate the method by describing a typical multiconnection multiparty service. The work presented within this paper is based on the results of the RACE MAGIC pr

ISSN:1074-5351    

DOI:10.1002/dac.4500070204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractSophisticated signalling protocols are required to properly handle the complex multimedia, multiparty services supported by the forthcoming BISDN. The implementation feasibility of these protocols should be evaluated during their design phase, so that possible performance bottlenecks are identified and removed. In this paper we present a methodology for evaluating the performance of BISDN signalling systems under design. New performance parameters are introduced and their network‐dependent values are extracted through a message flow model which has the capability to describe the impact of call and bearer control separation on the signalling performance. Signalling protocols are modelled through a modular decomposition of the seven OSI layers including the service user to three submodels. The workload model is user descriptive in the sense that it does not approximate the direct input traffic required for evaluating the performance of a layer protocol; instead, through a multi‐level approach, it describes the actual implications of user signalling activity for the general signalling traffic. The signalling protocol model is derived from the global functional model of the signalling protocols and information flows using a network of queues incorporating synchronization and dependency functions. The same queueing approach is followed for the signalling transfer network which is used to define processing speed and signalling bandwidth requirements and to identify possible performance bottlenecks stemming from the realization of the related protoc

ISSN:1074-5351    

DOI:10.1002/dac.4500070205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractThe control system of a BISDN network will undoubtedly be very complex to design, implement and maintain. Its complexity has led researchers to look for ways of breaking down the problem into smaller and manageable parts. This has motivated the use of an object‐oriented approach to analyse and comprehend the BISDN control system.This paper thus presents an object‐oriented analysis (OOA) of a BISDN control system. This analysis is based on a method introduced by Coad and Yourdon and comprises five steps. All five steps, namely identifying subjects, identifying objects, identifying structures, defining attributes, and defining operations, will be worked out in detail with an emphasis on the user network interface (UNI) signalling protocol object. Four subjects, nine objects, and three structures are identified in the problem space at hand. This structuring offers a framework to analyse in detail the three aspects, data, structure and dynamic behaviour, of the UNI signalling protocol.A parallel between this approach and the well known approach used by the International Telecommunication Union (ITU) for specifying signalling protocols and contained in Recommendation I.130 is drawn.The Coad and Yourdon OOA approach applied to a BISDN control system can be used for the analysis of different aspects of such systems. This paper focuses on the UNI signalling protocol object which leads to a complete specification. Any protocol resulting from such analysis can be claimed to be object‐oriented protocol. This approach offers modularity and thus offers a way of structuring the problem space into identifiable objects and data. Full benefits of object orientation can be gained only in the consistent use of object orientation throughout all steps in the development process. The proposed approach allows one to create libraries of generic procedures which can be reused in specific implementa

ISSN:1074-5351    

DOI:10.1002/dac.4500070206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractThis paper analyses the problem of providing call, connection, channel, and service control in broadband and intelligent networks to support a wide variety of services. A formal methodology called object‐oriented analysis (OOA) is used to analyse this problem. Three types of OOA models are constructed: the information model, state models and the object communication model. From these models, a distributed call processing architecture that proposes separate servers for call control, connection control, channel control and service control, is derived. Based on the events used for inter‐object communication in the object communication model, service‐specific and control‐function specific application service elements are defined as client‐server based

ISSN:1074-5351    

DOI:10.1002/dac.4500070207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractThe experimental ATM network services environment (EXPANSE) prototype provides an experimental testbed for multimedia multiparty telecommunications services over heterogeneous communications networks. The EXPANSE software architecture supports the functional separation of call and connection control. At the call control layer an object‐oriented, transaction‐based call model provides for the co‐ordination of the negotiations among users for the establishment, modification and disconnection of telecommunications services. The connection control layer provides an object‐oriented protocol for the dynamic establishment, modification and release of network connections which include the control and allocation of network resources required for multimedia multiparty services.The EXPANSE software includes an application programming interface (API) to the signalling protocol at the call control level. The API provides a uniform and powerful interface to the call model and allows different applications to co‐ordinate the control of local resources and sess

ISSN:1074-5351    

DOI:10.1002/dac.4500070208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

ISSN:1074-5351    

DOI:10.1002/dac.4500070201

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY