智能建筑的AMP综合布线工程

AMP综合布线系统是一种通用型开放的传播平台,其特征是仅以一种传输路线满足多种通信业务终端的技术要求,再加上用多媒体终端集语音、数据、图像于一体的通信应用方式,给用户带来很大方便和经济实用的效果,在智能建筑布线系统中具有广泛的应用价值。文中提供了AMP综合布线标准,对基于此标准的AMP综合布线系统测试工程进行了较为详细的分析和讨论。     

Connections and connectionless data transmission

The complementary concepts of connection-mode data transfer and connectionless data transmission are the fundamental models of communication in the architecture of Open Systems Interconnection (OSI). As the names imply, connection-mode data transfer involves the establishment and maintenance of a connection, which represents a dynamically negotiated agreement concerning the transfer of a series of related units of data; connectionless data transmission relies only on the prior knowledge that peer entities have of each other to transmit independent, unrelated data units, and does not involve the establishment of a connection. The two concepts together describe all of the peer-to-peer interactions that take place in the OSI environment. The national and international organizations concerned with OSI have applied these concepts successfully in the development of OSI service and protocol standards.     

A comparison between the OSI reference model and the B-ISDNprotocol reference model

The author presents views on the relationships between the Open Systems Interconnection (OSI) reference model (RM) and the broadband integrated services digital network (B-ISDN) protocol reference model (PRM), in an attempt to facilitate an interconnection between B-ISDN and data networks conforming to the OSI standards. According to the International Telecommunications Union-Telecommunications Sector (ITU-T), the exact relationship between the lower layers of the OSI RM and the B-ISDN PRM is for further study     

The OSI file service

The OSI File Service defines a standard for transferring, accessing, and managing information stored in or moved between open systems as files. Within the framework defined by the OSI Reference Model the OSI File Service resides within the Application Layer (OSI layer 7). The OSI File Service describes features for basic file transfer and access allowing manipulation of the data contained in a file and features for management of individual files. To minimize the amount of detailed technical information that one needs to determine about a system before communicating with it, the OSI File Service establishes a common model for files. The model used by the OSI File Service is called the Virtual Filestore. Describing file transfer, access, and management in terms of the Virtual Filestore allows interconnection of a wide range of systems of different complexity. The definition of a number of optional subsets within the Virtual. Filestore allows simpler systems to interwork with more sophisticated ones. The OSI File Service defines the aims and objectives that the protocol must achieve. The application protocols for the OSI File Service support the activities required for file transfer, access, and management between open systems.     

Structured cabling comes of age

Structured cabling has emerged as a basic building utility, comparable to heating and air conditioning, electricity or plumbing. it forms the essential communications infrastructure of a business's IT system, and is every bit as important as the equipment connected to each end of a piece of cable. Cabling is often overlooked or taken for granted, but a little time and effort in the choice of cabling system will save time, money and frustration in the near term, and, in the longer term, minimise the need for disruptive upgrades. A key objective for any structured cabling system is the capacity to handle with speed and reliability the huge data streams encountered in modern Internet and e-commerce applications. The system should also be capable of fast installation and deployment, which means that cabling components need to be modular, simple to use and, ideally, supplied in pre-qualified form. The author reviews the role of structured cabling in enabling the office IT infrastructure-today and into the future     

数据中心网络综合布线研究

介绍了数据中心的结构化综合布线系统的组成、建设原则以及各关键子系统的工作原理,通过数据中心建设的综合布线范例演示,为建设具有实用性和先进性的数据中心提供一定的参考。     

Integrating ISDN and OSI: an example

A successful multivendor trial demonstrating the integration of Open Systems Interconnection (OSI) and integrated services digital network (ISDN) technologies is discussed. The planning, staging, and results of this trial, which demonstrated ISDN as a viable transport technology for OSI data applications, are detailed. The technical requirements to be fulfilled and the initial plans are outlined. The actual configuration used is described, and the results are summarized     

Magnetic induction based cluster optimization in non-conventional WSNs: A cross layer approach

Conventional Radio Frequency (RF) communication technique is unsuitable for communication in non-conventional media (water, soil, rocks, etc.) because of heavy losses incurred due to dynamic channel characteristics. Magnetic Induction (MI) communication overcomes these losses as it is least affected by such varying channel characteristics. In non-conventional media based Wireless Sensor Networks (WSNs) the deployed sensor nodes cannot replace or replenish their batteries. Thus, energy consumption should be minimized and that can be achieved by clustering process. This process involves data sensing, aggregation and routing to the base station. These sub-tasks are performed under Physical (PHY), Medium Access Control (MAC) and Network (NET) layers of OSI Network model. Having lesser or larger number of clusters has different impact on energy consumption in different layers’ perspective. A large number of clusters decreases energy consumption as per PHY layer whereas it results in increased energy consumption as per MAC and NET layers. Thus, a trade-off is required to minimize the overall energy consumption. To this end, we found an optimal number of clusters considering the simultaneous influence of all three layers. The above analysis is performed for three media viz. sea water, fresh water and dry soil.     

Mapping the X window onto open systems interconnection standards

The issues involved in integrating X11 and open systems interconnection (OSI) are explored and potential solutions to implementation problems are given. OSI standardization issues are discussed, including naming and registration conventions and the current status of this work effort in national and international standards bodies. The direction of OSI in window management, X11's relationship to the OSI reference model and, in particular, the use of OSI association control and presentation services are briefly addressed. The potential impact on the OSI market and the global view of this work are discussed, from a research and from an international standardization perspective, along with the issues evolving from the prototype built and the likely commercial provision of X11 products supporting OSI     

Business data usage of OSI

Major uses of OSI will be to support business data communications, e.g., the financial industries, commerce, and electronic messaging. Aspects of OSI usage are seen by examining the business application standards dealing with information movement, particularly protocols, formats, and protocol data elements. This paper analyzes selected business data standards for relevance to OSI. Common usages are seen in comparing the information to be conveyed and the operations indicated by the protocols serving diverse business interests.     

Alternative software architectures for parallel protocol executionwith synchronous IPC

The use of parallelism in enhancing protocol execution performance is examined. In particular the use of a separate concurrent task for each protocol layer is discussed. Two layers of the OSI protocol system were implemented and run on a multiprocessor, with from one to five processors at each end of the connection. Potentially concurrent entities included user tasks as data source and sink, the OSI session layer (kernel functional unit only), the OSI transport layer (classes 0 and 2), vestigial network tasks, and tasks to buffer data between layers. Three substantially different design architectures with from nine to twelve tasks at each end of the connection were compared. The design differences centered on different ways to provide interlayer coordination and buffering; the protocol code was kept identical. The implementation used a real-time kernel which provides synchronous (request-reply) interprocess communication. The variation in throughput between designs covered a range of approximately two to one. The best design is found to be symmetrical decentralized two-way pipeline with courier communications     

The OSI reference model

The early successes of computer networks in the mid-1970's made it apparent that to utilize the full potential of computer networks, international standards would be required. In 1977, the International Standards Organization (ISO) initiated work on Open Systems Interconnection (OSI) to address these requirements. This paper briefly describes the OSI Reference Model. The OSI Reference Model is the highest level of abstraction in the OSI scheme. The paper first describes the basic building blocks used to construct the network model. Then the particular seven-layer model used by OSI is briefly described, followed by a discussion of outstanding issues and future extensions for the model.     

某会展中心的综合布线系统设计

综合布线系统GCS（generic cabling system）是智能化建筑的最基本的基础设施，被称之为智能化建筑的神经系统，它既能使话音与数据通信设备、交换设备以及其它信息系统之间彼此相连，又能实现内部设备及系统与外部通信网络的相连，是现代建筑物群落连接和信息传输的基础设施系统。     

智能建筑中高效网络布线技术的研究

当前,智能建筑开始出现在人们的视野中,其所具备的功能优势极为明显,而在智能建筑施工环节中,高效应用网络布线技术,是一项较复杂且重要的工程。网络布线工作的有序开展,需要电气保护技术的支持。通过高效网络布线给建筑物提供信息传播途径,可以达成智能化传递信息、管理控制的目的,因此要做好研究分析工作。在设计智能化高效网络布线时,需考虑建筑物实际需求,制定科学合理的方案,进一步提高智能化高效网络布线设计的施工质量。基于此,智能建筑中网络布线技术的有效应用,能提高整体建筑物的综合质量与水平。     

EMC Part Ⅶ： Cabling

Anyone working in a systems electromagnetic compatibility environment is usually painfully aware of the fact that, often, the weakest link in the system is the cabling. Whether this is the cable or the connectors themselves, or more likely the interface between the cable and the connectors where there may be a poor connection of the cable screen, the ability of cabling to leak or absorb spurious signals is a cause of much EMC frustration. This section will address the basis of the cabling related EMI phenomenon and the best cabling practice.     

Echelon-networking control

Distributed manufacturing control offers more functionality than centralised systems, but normally at the cost of coordination and `intelligence'. Here, the author describes a unique solution from Palo Alto-based Echelon Corporation and its semiconductor partners, Motorola and Toshiba. Instead of simply defining a network protocol, Echelon has developed a sophisticated microcontroller (the Neuron) with networking and interfacing built in. Neuron networks can run on various media, including twisted pair, radio or power lines. The system uses an OSI seven-layer network protocol, involving three microprocessors in a classic multiprocessing environment, using shared memory as their communication link. Advanced manufacturing techniques have integrated the three processors with memory at a cost comparable with an off-the-shelf single-chip microcontroller     

Analysis of transport measurements over a local area network

Measurements of the end-of-end delay and maximum throughput are reported for a typical implementation of the bottom four layers of the Open Systems Interconnection (OSI) protocols. These comprise the transport, network, data link, and physical protocols. An overview of the four protocols is given, and the experimental environment is described. The measurement results are discussed, and some of the implementation factors that affect the performance of OSI protocols are identified     

电子设备三维布线工艺技术应用研究

电子设备传统的工艺布线主要是根据实物及其接线关系构建线束,绘制二维平面图,在样板上制作线束.因应电子设备模块化、集成化和批量化的发展趋势,介绍了在Pro/E软件制作三维图的基础上进行三维布线构建数字化样机,并与二维布线比较,分析了三维布线对电子设备带来的影响,介绍了三维布线工艺的应用研究情况.