Distributed resource management and connection control for a multi-access interface to a broadband ISDN (BISDN)

A customer premises network (CPN) provides a common communications fabric to efficiently integrate the traffic of multiple terminals on a common access interface to a BISDN. An important consideration in choosing a CPN architecture is to facilitate terminal portability and application transparency, so as to accommodate standard broadband terminals and applications, requiring only minor modification to adapt them from the standard BISDN interface to the multi-terminal environment. This paper explores the multi-faceted issues of CPN transparency with an emphasis on the evolving BISDN control and management architecture. We introduce a control architecture that conforms to a rigorous separation between ‘call control’ and ‘connection management’. This allows the CPN to be transparent to the user to network signalling exchange, and to participate only in the connection management via a remote resource management protocol. More generally, this scheme allows a call control entity located in a local exchange node (LEN) to manage a distributed set of resources such as switches and multiplexors (and CPNs). This is achieved through the definition of a standard interoperable interface between the central call control entity and the connection control entities which may be remotely located in various network elements. The features and functionality for such an interface, which we term the bearer connection control interface, are described within the framework of the OSI remote management architecture. A standard remote resource management protocol allows for the co-operative sharing of resources across administrative domains. Although the importance of such a scheme is particularly visible as applied to remote CPN management, it is useful in other application domains where it is advantageous to distribute management processes.     

Object-oriented analysis of signalling and control in broadband networks

This 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 protocols.     

Management of capacity and control in broadband ISDN

The trend towards integration of services onto a single network and the addition of accompanying control features has led to an increase in the complexity of functional signalling protocols. A continuing dramatic reduction in the cost of traffic-carrying capacity has meant that call control costs are becoming an increasingly significant component of the total network cost. In BISDN, the support of many diverse services may result in an excessive control cost. To avoid this potential problem, virtual paths may be used. Capacity may be reserved on virtual paths to simplify the set-up procedure for individual calls. One benefit of this approach is that the cost of establishing a virtual path is shared among all individual connections which subsequently use it. However, this reduced control cost comes at the expense of installing additional traffic carrying capacity. This paper describes techniques for the management of traffic carrying capacity and control mechanisms in BISDN and presents a cost-benefit analysis to determine policies for reserving capacity on virtual paths. Significant savings in the total BISDN cost can result from the use of virtual paths.     

International standards for the broadband ISDN user-network interface

Recently, a series of international standards on broadband ISDN were approved in CCITT Study Group XVIII. These standards establish fundamental details on transmission, multiplexing and switching for broadband aspects of ISDN. This article reports on the current definition of the BISDN user-network interface. The UNI reference configuration, physical medium, rates, structure, ATM functions, and operations and maintenance functions are addressed with consideration given to open issues and the direction of future standards activities. Objectives for the UNI capabilities have generally been met with the current CCITT specifications. Some of the UNI physical layer ‘options’, however, potentially impose networking cost penalties.     

Object-oriented communication structures for multimedia datatransport

The evolving multimedia applications generate requirements for complex transport capabilities, i.e., functional features, in the end-to-end communication system such as handling of heterogeneity among communicating terminals, supporting finer levels of user-specifiable quality of data transport service, and synchronization of various data streams for delivery at users in real time. Accordingly, the communication system may be viewed as extending the basic capabilities provided by the backbone network (e.g., bandwidth allocation) into a set of transport capabilities suitable for complex applications. This paper presents: (1) an object-oriented view of the user interface to the communication system with an elegant separation of data transport functionalities, and (2) an approach to the design of underlying transport protocols. The object-orientation decomposes an application-level data transport into a set of network channel objects, with each channel object handling a separate data stream. The object interactions are modeled using a “data-flow programming” style, which allows a richer set of protocols to implement the communication system and offers flexibility to accommodate complex and heterogeneous subscriber services/terminals. The “data-flow programming” method also allows a high degree of communication level parallelism among data transport through channels. The view of a multimedia communication system as a “parameterizable black-box”, as underscored in the object-oriented structuring, allows easier interworking of the communication system with existing networks and easier integration of multimedia transport into programming environments     

基于Hibernate的轻量级J2EE架构

J2EE是业内一致认为非常优秀的软件架构,并在各种大型应用系统中得到广泛的应用.面向对象的分析方法是大家所熟知的科学的系统分析方法.基于关系型数据库在J2EE架构中使用OOA方法时,我们必须解决对象、关系的映射这一关键性问题.针对对象关系的映射和持久数据的访问,论述了采用Hibernate构建一个功能强大而又简洁、灵活的轻量级J2EE架构的方法.     

Design, analysis, and implementation of a telemedicine remoteconsultation and diagnosis session playback using discrete event systemspecification

Telemedicine remote consultation and diagnosis (RCD) software is a complex and distributed system. RCD allows physicians to collaborate on radiology or pathology cases from distributed geographic locations. It is very important to simplify design, construction, and maintenance of such a system. Currently, an object-oriented design methodology is used to design and develop a software system in a modular fashion. Object-oriented software is made of various objects that work together. From the design of the software system, we get information about object methods and inheritance. We also get information about which objects are contained in a particular object and which objects are used by another object. One important element that the traditional object-oriented design misses is time. We propose the use of discrete event system specification (DEVS) in the design and analysis of a software system, such as RCD. With DEVS, coupling between objects can be specified explicitly and an object behavior can be shown in time. We introduce DEVS, show the time-line analysis of remote consultation and diagnosis session playback using DEVS, and then describe its implementation     

B—ISDN宽带UNI信令点到多点配置的实现

本文根据ＩＴＵ－Ｔ最新的Ｑ．２９７１协议，以及笔者所从事的实际课题，提出一整套Ｂ－ＩＳＤＮ第三层ＵＮＩ信令的软件实现策略，其特点是能同时满足用户对点到点以及点到多点广播这两种通信方式的要求，而且可以动态配置。     

An analysis of the MMS object model

MMS (Manufacturing Message Specification) is an OSI application protocol designed for the remote control and monitoring of industrial devices. In this paper, we study the MMS object model: the notion of class, naming, inheritance and structuring. We show that MMS is designed for simplicity but that some notions are not dealt with homogeneously in all classes of MMS objects     

The ATM Forum's private network/network interface

The ATM Forum completed the first version of its private network/network interface (PNNI) in March 1996 and many ATM switch manufacturers are now offering early implementations. PNNI offers a different type of internetwork or internodal interface from the traditional Signalling System No 7 based approach favoured to date by 'public' network operators, such as BT. In spite of its name, however, PNNI may find its place in network service provider networks as well as in 'private' or customer networks. Some of the perceived limitations of the current specification for such an environment are currently being addressed in version 2, tentatively due for completion in the second half of 1998.The PNNI really consists of two parts, a signalling protocol based around the ATM Forum's UNI signalling specification, and a dynamic source routeing protocol. This paper aims to provide an overview of the functionality and mechanics of PNNI, and to compare and contrast with the functionality offered by ITU-T's B-ISUP.     

Knowledge-based approach to sleep EEG analysis-a feasibility study

A knowledge-based approach to automated sleep EEG (electroencephalogram) analysis is described. In this system, an object-oriented approach is followed in which specific waveforms and sleep stages ("objects") are represented in terms of frames. The latter capture the morphological and spatio-temporal information for each object. An object detection module ("frame matcher"), operating on the frames, is employed to identify what features need to be extracted from the EEG and to trigger the appropriate "specialist"--specialized signal processing modules--to obtain values for these features. This leads to an opportunistic approach to EEG interpretation with quantitative information being extracted from the signal only when needed by the reasoning processes. The system has been tested on the detection of K complexes and sleep spindles. Its performance indicates that the approach followed is feasible and can become a powerful tool for automated EEG interpretation.     

基于UML的面向对象的系统建模

UML是一种通用的可视化建模语言，用于对软件进行描述、可视化处理、构造和建立软件系统的文档。它是面向对象分析和设计过程中重要的建模工具。本文以办公自动化系统的建模为实例，介绍了一种基于UML的面向对象的系统建模方法。     

ATMUNI信令的功能划分

ＡＴＭ用户－网络接口（ＵＮＩ）信令采用ＯＳＩ的分层结构,本文首先简要介绍了ＡＴＭＵＮＩ信令协议的体系结构以及各层的功能。然后详细描述了ＵＮＩ信令功能模块的划分,以及各模块的功能。     

Terminal-to-network communication in an ATM-based ISDN

This paper addresses the topic of signalling and connectionless data transfer virtual channels in ATM at the UNI. It recapitulates on the access signalling support in narrowband ISDN, as a representative of an STM network and the predecessor of the coming broadband ISDN. Also, the influence of the customer premises network architecture is taken into account. From there, it is investigated in which ways these principles can be extended, into a general access infrastructure and access configuration management for signalling and connectionless services in the ATM-based broadband ISDN. Some possible implications for the internal architecture of the CPN and the network are discussed. This brings some insight into the restrictions which standardization of these principles at the UNI may bring along for the architecture.     

Automatic labeling and characterization of objects using artificial neural networks

Existing NASA supported scientific databases are usually developed and managed by a team of database administrators whose main concern is the efficiency of the databases in terms of normalization and data search constructs. The populating of the database is usually done in a manual fashion by row and column as the data become available, and the data dictionary is usually defined by the same team (at times with little input from the end science user). This process is tedious, error prone and self-limiting in terms of what can be described in a relational Data Base Management System (DBMS). The next generation Earth remote sensing platforms [i.e., Earth Observing System (EOS)] will be capable of generating data at a rate of over 300 Megabits per second from a suite of instruments designed for different applications. What is needed is an innovative approach that creates object-oriented data-bases that segment, characterize, and catalog, and are manageable in a domain-specific context, and whose contents are available interactively and in near-real-time to the user community. This paper describes work in progress that utilizes an artificial neural net approach to characterize satellite imagery of undefined objects into high-level data objects. The characterized data is then dynamically allocated to an object-oriented database where it can be reviewed and accessed by a user. The definition, development, and evolution of the overall data system model are steps in the creation of an application-driven knowledge-based scientific information system.     

OAM mechanisms for BISDN UNI and access networks

This paper clarifies operation and maintenance (OAM) requirements for broadband integrated services digital network (BISDN) customer access systems including user-network interface (UNI), and proposes basic OAM mechanisms. Access networks employ a logical networking architecture based on the asynchronous transfer mode (ATM) virtual path (VP) concept to provide all services efficiently, economically. Services are independent of the network's physical configuration. Thus, OAM functions for the access network are required to support physical and ATM layer capabilities. UNI physical performance and failure information flows to ensure user service quality are described. A fault localization mechanism is introduced that determines whether the failure lies on the network provider side or customer side. It uses failure information flows and loop back testing at the network terminator 1 (NT1). As connection-related virtual path connection (VPC) availability indication is necessary for user-to-network applications and user-to-user applications, two alternative VPC-related availability indication mechanisms are studied. Furthermore, basic performance monitoring mechanisms for ATM layer are described.     

World-wide standardization of broadband ISDN

A growing market demand for high-performance voice, data, image and video networks, coupled with advances in high-speed technologies has heightened interest in broadband ISDN (BISDN) throughout the world. Network providers, equipment manufacturers and standards bodies are working jointly to accelerate the definition of BISDN interfaces in anticipation of emerging market opportunities. BISDN is being designed as the foundation upon which to implement very flexible, high-bandwidth, high-performance networks. A multiplexing concept called asynchronous transfer mode (ATM), which can offer bandwidth on demand at rates exceeding 150 Mb/s, high-speed packet switching, and an efficient protocol which adapts existing information streams into the ATM format are key attributes of the emerging BISDN network standards. This paper reviews the motivations behind BISDN, explains its key attributes and challenges and discusses possible strategies for evolving today's network toward BISDN.