Modified filtering algorithm (MFA) for backbone interconnection-hardware design and implementation issues

Performance issues of the FDDI-II protocol, an upward-compatible enhancement of the basic fiber distributed data interface (FDDI), are discussed. The main characteristics of the FDDI protocol are examined. The performance of FDDI-II is studied for scenarios including asynchronous traffic, synchronous traffic and isochronous traffic. The results make clear that basic FDDI meets the requirements imposed by traditional local area network (LAN) application and that from a performance point of view FDDI-II is an excellent candidate for complex communications environments. When compared to the distributed-queue-dual bus (DQDB) protocol, FDDI-II yields much better efficiency in traditional LAN applications. >

FDDI-2 is an extension of the fiber distributed data interface (FDDI) standards that integrates isochronous circuit switched services with the timed token protocol packet services of FDDI. An expression is derived to describe the effects of hybrid mode operation on the packet channel token rotation time, which is dependent on the maximum isochronous transmission rate. The management of packet data in several possible latency adjustment buffer (LAB) implementations during steady state and programming template changes is described. One basic choice is to operate the LAB as a strict FIFO, keeping a fixed network delay, and another performs more efficient delay management by bypassing the isochronous delay when possible. LAB operation and programming template changes greatly affect the operation of the packet channel. Both affect the range of the token rotation time that is used in the packet channel.

In this paper, we present a performance analysis of how effective video server applications can be supported on personal computers (PCs) connected through a local area network (LAN). We considered both the standard 16-Mbit/s token ring and a 100-Mbit/s token ring, which follows closely the specifications for the Fiber Distributed Data Interface (FDDI). We examined three I/O architectures for a PC-based video server: an interrupt-driven I/O architecture, a peer-to-peer I/O architecture, and a concurrent, object-based I/O architecture that we proposed. The video server must support multiple MPEG-1 video streams at the same time to multiple clients on the LAN. We found that the network protocol layers require a lot of processing power, and that an implementation of our proposed I/O architecture, which takes advantage of the available power of the host processor to off-load I/O adapters, can deliver much better performance, and is more cost-effective, than other I/O architectures in a video server environment.

Carring is a cost-effective, reliable, real-time local area network for cars that is based on a ring topology. Applications of Carring are mechatronic systems in cars, but it is also applicable to general LANs. This paper introduces different medium access methods for Carring. Carring applies synchronous time slots for medium access together with an extension algorithm that allows reallocating unused time slots, thus achieving maximum bandwidth utilization of the ring. Another way of efficient bandwidth allocation in Carring deals with the usage of release algorithms. Furthermore, the fibre distributed data interface (FDDI) is described in order to compare it with Carring.

The survivable adaptable fiber optic embedded network (SAFENET) program, an effort by the US Navy to develop standard computer network profiles that meet the requirements of navy shipboard mission-critical computer systems, is discussed. The two SAFENET standards currently in development are described. The distinction between them is restricted to the commercial local area network (LAN) upon which each is based. SAFENET I uses the IEEE 802.5 token ring LAN, which operates at 16 Mb/s. SAFENET II uses the fiber distributed data interface (FDDI) LAN, which operates at 100 Mb/s. The SAFENET transmission system, optical power budget, and application methodology are examined. >

The Advanced TOMAHAWK Weapons Control System (ATWCS) is being developed to support current and future tactical cruise missiles onboard navy ships. The ATWCS utilizes the Navy's standard Tactical Advanced Computer (TAC) 3 components and commercial standard Local Area Networks (LANs) to provide a flexible, robust system with excellent growth potential. Aggressive use of systems engineering principles has refined the system design so that it is adaptable to various Navy platforms. An excellent example of the success in meeting this design goal is the Submarine ATWCS.The primary data pathway for ATWCS is a Fiber Distributed Data Interface (FDDI) LAN connecting the four TAC 3 processors. Existing Common Display Consoles (CDCs) are used for display and control of the TAC 3 processors. The Submarine ATWCS builds on software already developed for surface ships. The open system architecture of this software is based on Computer Software Configuration Items (CSCIs) and several are obtained from other programs. Direct weapons interface in the Combat Control System (CCS) provides optimum efficiency in weapons control while gaining the functionality advantages of ATWCS.This paper describes the systems engineering solutions for both software and hardware to achieve a modern cruise missile weapons control capability for submarines utilizing non‐development items (NDI). Commercial Off The Shelf (COTS) technology, LANs and open system architecture.

The author examines two broadly supported ring designs, IEEE 802.5 and the Fiber Distributed Data Interface (FDDI), X3T9.5 currently emerging as local area network (LAN) standards, and explores the basis of this interest in ring topologies. The advantages that ring designs offer are presented, and on this basis a proliferation of rings is envisioned for the next decade.

In modern times, where the speed of transmission is of utmost importance, often need arises for a reliable transmission medium. With innovations in LAN (local area networks) such as FDDI (fiber distributed data interface), fiber optic data links and associated interface schemes are gaining more and more acceptance and actually are becoming real necessities. In this article, the author describes a simple design methodology for a fiber optic data link and presents criteria to evaluate the performance and frequency response properties of these data links. In addition, a simple wavelength division multiplexing (WDM) scheme for improved data rate is also presented.

The aim of this work has been to graphi cally simulate the protocols employed for 100 Mbps token ring local area network (LAN), using the fiber-optic medium, known as Fiber Distributed Data Interface (FDDI), and to study its performance evaluation. In the computer based simulation, the effort has been made to describe the working of the protocols using graphical, dynamically working models. Also performance characteristics, such as Throughput Vs Token rotation time, Throughput Vs Ring Latency, Throughput Vs Data Arrival Rate are obtained. The asynchronous priority level throughput for different data arrival times are tabulated. From the characteristics, it is found that the relative difference between the ring latency and the token rotation time (TRT) has a significant effect on the maximum total throughput. Also with the higher value of the TRT the throughput increases faster compared to lower TRT values.

Techniques for achieving data rates up to 155 Mb/s over unshielded twisted pair wiring in premises distribution systems are described. These high data rates represent an improvement of about an order of magnitude in speed when compared to presently available data rates for local area networks operating over this communication medium. The transmission scheme proposed for achieving these higher data rates is carrierless AM/PM (CAP), which is a bandwidth-efficient two-dimensional passband line code. It is shown that a 32-CAP line code can be used to provide the fiber distributed data interface (FDDI) rate of 125 Mb/s over 100 m of voicegrade unshielded twisted pair (UTP) wiring in a channel bandwidth of 30 MHz, which results in a robust performance and eliminates potential problems with electromagnetic radiation limits above 30 MHz. >

This paper discusses single and multiple token rings, describes major aspects of their architecture, and discusses in detail the performance issues arising in the design of such local area networks. Following a survey of analytical queueing models to describe the basic token-ring operation, three topics are discussed in detail: 1) The IEEE 802.5 Token Ring and its performance; 2) performance aspects of the ANSI Fiber Distributed Data Interface (FDDI) token ring, and 3) performance questions arising in the interconnection of token-ring networks.

Fiber optic local area networking (FOLAN) is rapidly becoming a reality. It has gone from an engineering curiosity to a commercially available product within the last few years thanks to the emerging standards and general acceptance of fiber optics. FOLANs are ideal for high speed data transport. They eliminate ground loop problems; the media does not require shielding and, in general, requires less space and is lighter weight. Fiber optic media has a much higher bandwidth than equivalent wire systems which will allow for future expansion without requiring a cable plant change. The question of what is presently available and how a typical system is implemented will be answered. There are several FOLANs commercially available or under development at this time. Generically most of them fall in one of these categories: token rings, token buses, and continuous sense multiple access/collision detect (CSMA/CD) networks. Perhaps the most well-known token ring is the fiber distributed data interface (FDDI). One implementation of the token bus is the manufacture automated protocol (MAP). The most popular implementation of CSMA/CD is Ethernet. A brief description of each of the protocols, connection schemes, and available hardware used to implement the networks will be given. The FDDI network will be used to illustrate a typical network realization. The last portion of the presentation will discuss what the future has in store for high speed fiber networks. What are some of the emerging technologies? What is SONET, HPPI, and high-speed channel?

This paper studies an appropriate value of the maximum transmission rate under congested for IEEE802.11g wireless LAN by experiments with subjects. In our experiment, we studied the appropriate value of maximum transmission rate according to Quality of Experience(QoE) for Web services. This paper treats actual two Web services: Google map and Amazon. This paper studied the QoE-based appropriate values of the maximum transmission rate by experiment. As a result, for Google map, the value of the maximum transmission which can maintain high QoE regardless of the degree of congestion exists. However the most suitable maximum transmission rate was changed according to the number of user. On the other, for Amazon, the appropriate value of the maximum transmission rate does not change regardless of the number of user.

Improved method for wireless communication system based on NRF24L01 chip is addressed in this paper. By analyzing the structure and the sequence diagram of the single NRF24L01 chip, the maximal theory rate has been calculated out. The long settling time of antenna and the low air data rate are the bottleneck of the whole system. To improve the data transmission rate, a new method of many chips working at pipelining production mode has been designed out. The new wireless communication system uses at most 9 chips as the system core. By fully utilizing the single chip bottleneck time, the maximal theory data transmission rate of the new system is times to the single chip system.

We present a novel and mathematically sustained procedure for solving the deconvolution- filtering problem. The technique for obtaining a stable solution to the deconvolution (restoration) problem is based on the regularized functional Newman series of the operator equations and gives more precise results than traditional ones. Several novel rank filtering procedures were proposed for decreasing of noise influences. These procedures have given more accuracy and robust results in comparison with other known ones. The efficiency of the techniques proposed has been proven by numerical simulation analysis and by experimental investigations of different kinds of RS objects such as: (1) rural or vegetation covered areas sensed by three microwave frequencies airborne equipment; (2) forest fire areas, industrial installations at night, electrical structures, etc. sensed by infrared and visible sensors; and (3) tropospheric refractive index height profiles restoration by the satellite navigation system `CIKADA' data.