We have made investigated a new regional Personal-Computer(PC) communicationnetwork system for residential users beyond Small Office and Home Office (SOHO)'s users. It provides a cost-effective and user-friendly ...
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ISBN:
(纸本)0819423572
We have made investigated a new regional Personal-Computer(PC) communicationnetwork system for residential users beyond Small Office and Home Office (SOHO)'s users. It provides a cost-effective and user-friendly PC communication environment to community members by supporting connections group communication services with customized audio-visual user-interface and contents, moreover authenticating them on the Media Access control(MAC) destination address of the PC's. The user-interface is designed to start the PC communication without complex setup procedure, The members can use any protocol, because MAC address authentication is independent of the network layer protocol. This group communication services are offered by distributive bulletin board servers with Common Gateway Interface(CGI) and Hyper Text Transfer Protocol(HTTP), which are distinguished from the Net News and primary bulletin board for conventional system. This paper discusses, based on a pilot experiment in a small residential area, the network congestion caused by broadcast traffic and address conflict caused by belong to plural groups at the same time and presents a solution. We also discuss the impact of a new bulletin board server derived from traffic data based on our pilot experiment for interactive and audio-visual group communication. The server is operated by specified CGI program on HTTP server and capable to support a interactive communication environment in World Wide Web.
Todays networks are characterized by heterogeneous environments. Various transmission techniques coexist and offer different bandwidths at different costs, Because of video conferences and similiar applications becomi...
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This paper presents the OAM (operations, administration and maintenance) software architecture of the BRDS (broadband distribution subsystem) for an optical CATV network. We built an optical CATV network called SWAN (...
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ISBN:
(纸本)0780329163
This paper presents the OAM (operations, administration and maintenance) software architecture of the BRDS (broadband distribution subsystem) for an optical CATV network. We built an optical CATV network called SWAN (socio-cultural welfare advanced network) based on SDH (synchronous digital hierarchy) and FTTH (fiber to the home) technology. The BRDS is one of the SWAN subsystems. The OAM software of the BRDS consists of operating systems and application software. We describe the technical issues such as the implementation aspects, the development environment and the future plan of the OAM software for the BRDS.
This paper describes experiments conducted over ACTS that were motivated by the commercial potential of low-cost receive-only satellite terminals operating in a hybrid network environment. The first experiment tested ...
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A methodology for constructing parallel embedded DSP systems is described. The method uses a software and embedded processor abstraction to help raise the level of problem analysis above the raw state machine concept....
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Resource contention in packet switched all-opticalnetworks is being addressed in this paper through the combined use of fiber delay lines and 2×2 space photonic switches. With this basic approach, also known as ...
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Resource contention in packet switched all-opticalnetworks is being addressed in this paper through the combined use of fiber delay lines and 2×2 space photonic switches. With this basic approach, also known as Quadro or Switched fiber Delay Lines (SDL), the solution efficiency is linked to its storage capacity, determined by the combined length of the fiber delay lines. In the past, this capacity was given by the number of 2×2 photonic switches used, i.e., the number of stages in the receiver, which limited the solution by cost, mainly determined by the switch component, and by the signal power loss and crosstalk introduced by each switch. This work presents and analyzes the use of 'multi-buffer' fiber delay lines, in Quadro, so termed since in it multiple packets are allowed to be concurrently stored (propagated) on each delay line. In this way the total storage capacity is increased, while the proposed design utilizing novel switch control is shown to significantly improve receiver and network performance, without increasing the number of the 2×2 space photonic switches in the system, i.e., its cost.
This paper describes a set of software and experiments to demonstrate networkcontrol and management capabilities for a reconfigurable wavelength-division-multiplexing (WDM) all-opticalnetwork. This work is an early ...
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This paper describes a set of software and experiments to demonstrate networkcontrol and management capabilities for a reconfigurable wavelength-division-multiplexing (WDM) all-opticalnetwork. This work is an early prototype implemented in the first year of the DARPA Multiwavelength opticalnetworking (MONET) Project. The primary goal of the prototype experiment work was to demonstrate and assess the viability of implementing a WDM network's control and management (NC&M) system over a Common Object Request Broker architecture (CORBA) compliant reliable distributed platform. Another goal was to demonstrate the viability of using an embedded optical wavelength to support the NC&M system's data communication channels. This early prototype allows us to gain experience and to lay the foundation for our on-going work to develop the full-featured NC&M system in the MONET project's testbed and field trial experiments. This is an important step towards realizing the overall vision of the MONET project in the development of a flexible, reliable, high-capacity, high-performance cost-effective national opticalnetwork based on multi-wavelength fiber-optic technology.
While the Transmission control Protocol (TCP) generally provides robust performance across many network environments, several researchers have recently identified the poor end-to-end performance achieved by TCP on Asy...
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While the Transmission control Protocol (TCP) generally provides robust performance across many network environments, several researchers have recently identified the poor end-to-end performance achieved by TCP on Asynchronous Transfer Mode (ATM) networks. The performance problems arise for several reasons: (1) a size mismatch between TCP segments and ATM cells;(2) the simple protocols used for segmentation and reassembly in ATM, and for retransmission in TCP;(3) specific `optimizations' in TCP, made primarily for low-bandwidth Internet environments, which do not work well in high speed ATM networks;(4) features (or misfeatures) in most TCP protocol implementations;and (5) subtle interactions between all of these factors. This paper describes a simulation model that we have constructed to study TCP performance on ATM networks, as well as a set of simulation experiments conducted using the model. The TCP model is detailed enough to recreate many of the performance problems identified by other researchers, as well as to evaluate potential solutions to the performance problems. The TCP model adds to the traffic modeling toolkit available in our existing ATM network simulator, and enables the further study of performance issues in TCP over ATM.
An opticalnetworkarchitecture suitable for interconnecting base stations in a distributed microcellular wireless communications system is proposed. Base stations are grouped into one-hop subnets of size m each and c...
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An opticalnetworkarchitecture suitable for interconnecting base stations in a distributed microcellular wireless communications system is proposed. Base stations are grouped into one-hop subnets of size m each and connected by m/spl times/m star couplers. Each base station is affiliated with several subnets and has a tunable optical transceiver(s) over m distinct wavelength channels. The network can support N=m/sup D/ base stations, where D is the network diameter (typically 2,3). The multicast nature of the architecture lends itself to fast routing and mobility control schemes supporting point to multipoint connections. The networkarchitecture composed of wired and wireless segments, and corresponding addressing and routing schemes are described. The network is highly fault-tolerant, has a self-routing method and a near balanced load which results in high throughput and low delay. These features are discussed together with examples.
In the past, on-site or roving personnel monitored and repaired power equipment. Today, to increase efficiency and reduce costs, there is a trend to monitor equipment from a centralized maintenance location. This loca...
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In the past, on-site or roving personnel monitored and repaired power equipment. Today, to increase efficiency and reduce costs, there is a trend to monitor equipment from a centralized maintenance location. This location is responsible for monitoring all the equipment sites, responding to alarms, and scheduling service and repair as needed using the most appropriate service personnel. The telecommunication vendor must make many decisions when building the maintenance network. Some of the issues include: number of maintenance sites; type of central monitoring system; type of communication links; messaging protocol; alarms and data to be processed; prioritizing alarms; security; network and element failure; and remote operations. This paper discusses a general networking architecture and specific architectures using examples drawn from two different working systems: Bellcore's Transaction Language 1 (TL-1) and Telefonica de Espana's Sistema de Operacion y Conservacion (SOC). It also speculates on future architectures based on TCP/IP and SNMP protocols.
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