Software engineering

Software engineering has become both more and less simple since 1993 and 1994, when many questions were posed. Unfortunately, the answers that emerged in 1995 were less satisfying than many people had hoped they would be. The field is now simpler because, among other reasons, the purchasing clout of 70 million Windows users has made Microsoft's proprietary application program interfaces (APIs) a standard to which the rest of the software industry-or at least that portion dependent on Windows for its bread and butter-must adhere. An API is a set of rules for writing function calls that access functions in a library; programs that use API-compliant calls can communicate with any others that use the API, regardless of the others' specifics. In the past, several APIs would compete for market share. After a shakeout, the survivors would merge their APIs into a single industry standard controlled by a standards organization. But Microsoft's successes in operating systems and applications have transformed its Messaging API (MAPI), its OLE (formerly an acronym for Object Linking and Embedding but now treated as a word in its own right), and its Win32 (the API common to Windows NT and 95) into de facto standards that most developers know. Whether Microsoft's dominance is a boon or curse, it is a fact that they must accept     

自动交换光网络的标准化现状

国际上许多标准化组织都在对自动交换光网络的相关技术和标准规范进行研究。本文介绍了ITU－T、IETF和OIF等几个主要的标准化组织在自动交换光网络标准方面的进展情况。     

Distributed network computing over local ATM networks

Communication between processors has long been the bottleneck of distributed network computing. However, recent progress in switch-based high-speed local area networks (LANs) may be changing this situation. Asynchronous transfer mode (ATM) is one of the most widely-accepted and emerging high-speed network standards which can potentially satisfy the communication needs of distributed network computing. We investigate distributed network computing over local ATM networks. We first study the performance characteristics involving end-to-end communication in an environment that includes several types of workstations interconnected via a Fore Systems' ASX-100 ATM switch. We then compare the communication performance of four different application programming interfaces (APIs). The four APIs were Fore Systems' ATM API, the BSD socket programming interface, Sun's remote procedure call (RPC), and the parallel virtual machine (PVM) message passing library. Each API represents distributed programming at a different communication protocol layer. We evaluated two popular distributed applications, parallel matrix multiplication and parallel partial differential equations, over the local ATM network. The experimental results show that network computing is promising over local ATM networks, provided that the higher level protocols, device drivers, and network interfaces are improved     

开放式HFC网络管理系统综述

随着HFC网络技术的迅猛发展，网络规模更加庞大，结构更加复杂，只有通过适当的网络管理，强大的网络功能才能得到充分利用，而有效的网络管理及良好性能也成为评价网络的一个重要标准，正是由于HFC网络的这种迫切需求，美国电缆通信工程师协会（SCTE）混合管理分委员会（HMS）经过多年努力提出了一系列标准，形成了一套开放式HFC网络设备管理系统标准。     

Value-added services in the converged network

Now that the local market is open to competition, incumbent local exchange carriers as well as competitive LECs must not only follow the technology curve, but find a way to ride the wave of network convergence and offer innovative value-added services if they want to maintain their market share. Over the past decade, the intelligent network has been used to support value-added services. New APIs are being designed for the creation of value-added services spanning multiple domains (wireline/wireless, voice/data, public/enterprise). These APIs will not only ease the development of value-added services, but will also open service creation to third parties     

面向移动互联网的业务能力开放技术标准综述

移动互联网时代,创新能力和技术尤为重要。为满足用户业务使用需求,互联网商和电信运营商均聚焦业务能力开放技术,将典型业务能力对外开放,实现该领域商业模式的创新。文章针对面向移动互联网的业务能力开放技术国际国内标准进行系统地研究,尤其对开放接口进行了详尽的分析阐述,从而为电信运营商业务开展提供技术参考。     

Developing applications for Internet telephony: a case study on the use of parlay call control APIs in SIP networks

Applications offered to end users as value-added services, or more simple, services, are crucial for the survival and success of service providers. Two main sets of standards have emerged for Internet telephony: H.323 from the ITU-T and SIP from the IETF. Unfortunately, the related application development frameworks are rather weak. Parlay, a set of standard object-oriented and signaling protocol-neural APIs, is an alternative. It allows applications to access network functionality, including call control, in a controller manner. Call control makes it possible to establish, modify, and tear down calls. It is the main functionality offered by Internet telephony networks. We have built a call control application in a SIP environment, using the call control APIs offered by Parlay. The application is a multiparty game. This article describes the case study. The mapping of the APIs onto SIP is presented, and its implementation is described. Related work reviewed, and the lessons learned are discussed. Parlay call control APIs are suitable for application development in Internet telephony. However, well isolated extensions are needed to realize their full potential.     

The effect of industry standard setting on patent licensing andenforcement

Patent policies issued by standard-setting organizations help resolve the tension between enforcing patent rights and adopting open standards. In this article we examine the application of these policies to patent licensing and enforcement situations. An industry standard consists of a specified set of technologies adopted by an industry group in order to effect compatibility among products. The tension between enforcing proprietary intellectual property rights and adopting open industry standards has become a central issue for standards-setting bodies as well as the courts called on to enforce patent rights. As patent rights become more and more prominent in the global economy, the issues presented by the incorporation of patented technology into standards have become increasingly important. The ideal of open, widely promulgated standards is at odds with a patent owner's right to exclude others from making, using, or selling the patented invention. The ability of an industry member to exclude others from practicing a standard by asserting a patent that covers the standard would serve to undermine rapid and widespread adoption of the standard, resulting in reduced value of the standard. To prevent this situation, standard-setting organizations have developed patent policies that require their members to disclose intellectual property that may impact a proposed standard. Furthermore, patent owners are required to either forgo enforcement of patent rights against standard users, or promise to license their patents to all comers at a fair, reasonable, nondiscriminatory rate. Such a policy resolves many of the tensions between proprietary technology and the desire for an open, widely practiced standard. However, the implementation of such a policy is not as straightforward as may at first appear     

MPEG-M: A digital media ecosystem for interoperable applications

MPEG-M is a suite of ISO/IEC standards (ISO/IEC 23006) that has been developed under the auspices of Moving Picture Experts Group (MPEG). MPEG-M, also known as Multimedia Service Platform Technologies (MSPT), facilitates a collection of multimedia middleware APIs and elementary services as well as service aggregation so that service providers can offer users a plethora of innovative services by extending current IPTV technology toward the seamless integration of personal content creation and distribution, e-commerce, social networks and Internet distribution of digital media.     

Home systems standards: achievements and challenges

"Home systems" is a new consumer products industry. The market potential is very large, although the market has been evolving very tenuously. What is certain is that consumer demographics favor more conveniences for busy families and devices that assist those with physical limitations. Products based on home systems technology will serve both of these market segments. A variety of consortia and authorized standards bodies have been writing specifications for residential networks to provide a communications infrastructure for home systems and connections to external networks. This strategy of defining an infrastructure to support a nascent market is unusual. However, it offers the opportunity to specify a network without backward compatibility constraints, so often a requirement when upgrading and standardizing existing networks. This article addresses the fundamental question: has the home systems industry been successful in writing and adopting standards that promote industry growth? In part, the emergence of the home systems industry is a work in progress. Nevertheless, important standards and consortia programs have been developed since the mid-1980s. Some of the prominent achievements in home networks are reviewed. This article concludes that a clean slate offered by an undeveloped market is an advantage to standards writers. However, there needs to be a strong impetus to enter a potentially thriving market in order to motivate the standards writers to target and complete their work expeditiously. Otherwise, the writers will invest too much time perfecting their work, rather than making pragmatic compromises     

The Application of WSFL in the Parlay X Based Services Creation

1　Introduction　NGN abstracts beneath protocols as a set of easy under standing interfaces through open Application ProgrammingInterfaces (API). These APIs are independent with net works, so the services created with these APIs are irrespec tive to special network details[1]　ParlayXAPI is a set of more single and higher abstractedAPIs than Parlay API. These ParlayXAPIs have the abilityto access the network functions, and are easy to understandby IT developers to use in …     

Telecommunications management network: vision vs. reality

Since the early 1980s, the standards bodies have been specifying the telecommunications management network (TMN) principles. Millions of dollars have been spent. The TMN principles aim at being applicable across telecommunications technologies. They recommend the use of independent management networks to manage telecommunications networks, elements in the telecommunications networks (managed networks), and managing systems (in managing networks), communicating via well defined, standardized interfaces. The standards bodies envisioned TMN as a possible solution to the complex problem of telecommunications networks and services operation, administration, maintenance and provisioning (OAM and P) in the open, multivendor environment. However, the vision stumbles against the reality. Various factors still hinder the implementation of TMN-based OAM and P systems. The present article provides a tutorial on TMN by contrasting the vision and the reality     

加快海南电信事业发展促进海南国民经济信息化

海南自１９８８年来建省以来，经过８年努力，一改过去通信落后的面貌，网络规模，技术层次，服务水平都跃入全国先进行列。“九五”电信发展序幕已经拉开，今后的发展重点和工作方针已经确立，实施方案具体而详尽；提高电信网综合能力和技术层次，提高服务质量和服务水平，发展业务，开拓市场，采取措施加强维护管理方方面面齐头并进。     

Challenges in network management

The author notes that standard network management has certainly had a great impact on the industry. However, he further points out that it is important to distinguish between two kinds of standards, horizontal and vertical. Horizontal standards, such as management protocols and management objects, can at most provide a technology base for enabling products. However, in order to produce a robust market, vertical standards, such as APIs and a framework for management applications are needed. The author notes that the industry continues its struggle to distinguish between dreams and reality; `architectures' and marketeers are very good at seducing the industry's attention for long periods of time. Fortunately, it is the engineers who must ultimately deliver products that provide cost-effective solutions. As such, the outcome is uncertain, the author concludes     

Millimeter wave antennas

Major advances in millimeter-wave antennas have been made in recent years, in particular in two areas. A new class of leaky-wave antennas based on open millimeter waveguides has been proposed and investigated, and substantial progress has been achieved in integrated antennas where active and passive circuits, possibly in monolithic form, are combined with the radiating elements in one compact unit. Interesting developments have taken place also in a third group of millimeter-wave antennas, that of microstrip antennas and printed circuit antennas in general. An attempt is made to summarize these developments     

Open standards: a call for change - [ITU-T kaleidoscope]

Digital communication is both pervasive and vital across society. This creates a growing public interest in the technical standards that proscribe public communications. The public is demanding open standards. The rallying cry "Open Standards" means different things to different groups. This article reviews the different needs of specific groups of society and develops ten different requirements for open standards. To implement these requirements, changes to the rules and procedures of standardization organizations, international bodies (e.g., WIPO, WTO), and national patent office rules are proposed. Interestingly, technical changes, in the form of new standardized protocols, rather than legal or policy changes, appear to be the most important changes to meet the requirements of open standards."Standards function as feathers that guide the arrow of technology. While feathers are light and seemingly trivial on an arrow's shaft, without feathers, few arrows find their mark. Without standards, few technologies find their market"     

Network management considerations for interworking ATM networkswith non-ATM services

Rapid progress has been made on standards and implementation agreements for interworking ATM networks with frame relay, DS1/DS3 circuits, and SMDS. This article examines ATM network management issues in these interworking environments, with an emphasis on how each interworking environment has unique requirements for network management     

ASAAC标准体系架构述评

联合标准化航电系统架构协会(ASAAC)定义了先进航空电子体系结构(A3)的开放式标准、概念和指导原则,该标准和指导原则主要用于2005年以后新的飞机项目和现有飞机的升级计划。ASAAC标准定义了综合模块化航空电子系统(IMA),该标准是为了建立一个统一的IMA体系结构。IMA由通用的组件构成,这些组件可以在单独的标准中定义和说明。针对ASAAC标准定义的航电系统顶层体系架构,概述了该架构的一些设计指导原则,同时简要介绍了IMA架构。     

Opening up networks with JAIN Parlay

The desire for new business growth has been a major driving force towards the development of open network APIs, such as the Parlay API, within telecommunications networks. The Parlay API enables both third parties (external companies, operating outside the security domain of the network operator) and network operators to build new applications that rely on real-time control of network resources. The Java APIs for integrated networks (JAIN^TM) Community is defining a Java version of the Parlay API to bring the benefits of the Java language to the Parlay API, and to promote industry-wide adoption of the Parlay API. This article describes the background and rationale behind the work of the Parlay Group, together with the characteristics, structure, and capabilities of the Parlay API. The benefits that Java and the JAIN Community bring to the Parlay API are then explored. A technical overview of the Java version of the Parlay API, referred to as the JAIN Parlay Edit Group API, is given and illustrated using example sequence diagrams. The article concludes by taking a look at what additional features may be added to the API and the implementation activities that lay ahead