Wavelength Division Multiple Access Research Articles

AN OPTICALLY INTERCONNECTED DISTRIBUTED SHARED MEMORY SYSTEM: ARCHITECTURE AND PERFORMANCE ANALYSIS

This paper introduces an optically interconnected distributed shared memory system. The distributed shared memory approach integrates both shared memory and distributed memory system ideas to extract the strengths of each while balancing their respective weaknesses. The system is a system based on a photonic network to support the high communication requirement of . The employs wavelength division multiple access on the photonic network, enabling multiple channels to be formed on a single optical fiber. A result of the high communication capacity is the simplification of the global address mapping problem. This simplified uniform address allocation scheme is introduced. The advantages of the proposed approach are examined through a performance analysis based on a closed queueing network which has been validated through extensive simulation. The performance of the system is evaluated in terms of transaction time of a memory request and system throughput. The impact of variations in the number of channels and processors in the system on these metrics is studied. The effect of variations in memory and channel service times are also evaluated.

Performance Analysis of Single-Hop Wavelength Division Multiple Access Networks

Wavelength division multiple access (WDMA) provides a way to tap the huge bandwidth of an optical fiber by simultaneously operating on multiple channels at different wavelengths, with each channel running at the speed of the electronics of an end user station. This paper presents a mathematical model which approximates WDMA networks with general hardware configurations and arbitrary traffic patterns. Packets which cannot be transmitted upon arrival are blocked (i.e., lost) immediately. We first study the case of a uniform traffic matrix and observe that, when the number of wavelengths is fewer than the number of stations, it is better to have both tunable transmitters and tunable receivers, rather than having only either one of them tunable. Furthermore, we find that only a small number of tunable transmitters and receivers per station is needed to produce performance close to the upper bound. We then construct a general traffic model and propose an iterative solution procedure. A case of hot-spot traffic is studied using this model. We find that adding more resources to the hot-spot node will help improve its performance, but only to a limited extent determined by the traffic imbalance. The match between the model and simulation results are shown to be excellent.

Wavelength division multiple access channel hypercube processor interconnection

A hypercube-based structure in which optical multiple access channels span the dimensional axes is introduced. This severely reduces the required degree, since only one I/O port is required per dimension. However, good performance is maintained through the high-capacity characteristics of optical communication. The reduction in degree is shown to have significant system complexity implications. Four star-coupled configurations are studied as the basis for the optical multiple access channels, three of which exhibit the optical self-routing characteristic. A performance analysis shows that through the integration of agile sources or receivers, and wavelength division multiple access, systems can be developed with significant increases in performance yet at a reduction in communication subsystem complexity. >

A collisionless multiple access protocol for a wavelength division multiplexed star-coupled configuration: architecture and performance analysis

A collisionless wavelength-division multiple-access (WDMA) protocol for a passive star-coupled photonic network is introduced and shown to possess significant performance and flexibility advantages. A performance modeling technique based on a semi-Markov analytic model, which eliminates many of the unrealistic assumptions of past approaches, is introduced. The performance of the protocol is analyzed using this model and discrete-event simulation. Control channel access arbitration is achieved through time-division multiplexing (TDM), enabling all active nodes to transmit once every control cycle. The long synchronization delays typical of TDM systems are significantly reduced, because the control cycle length is proportional to the control packet size rather than the data packet size. The protocol eliminates packet collision and variable-sized data packets are supported without utilization degradation.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Tunable filters for dense wavelength division multiple access systems

A tunable Fabry-Perot filter is described in which the cavity length is continuously monitored by a capacitance sensor and servo-tabilized. The filter can be random access tuned over > 50 nm wavelength range at 1550 nm with a response time -1 in transmitted wavelength. The filter has been used as a spectral analyzer in laboratory test equipment, a demultiplexer, and in optical amplifiers for noise reduction and wavelength selection.

Channel capacity optimization of chirp-limited dense WDM/WDMA systems using OOK/FSK modulation and optical filters

Frequency chirp in semiconductor lasers that are directly modulated through carrier injection not only induces dispersion in long-haul single-mode fiber communication systems, but also causes energy loss and signal distortion when frequency selective elements such as Fabry-Perot filters are present. This effect is significant for high-bit-rate channels in a dense wavelength-division-multiplexed system in a LAN/MAN environment which requires narrow-band filters to suppress crosstalk from adjacent channels. A simulation approach is used to determine the channel capacity in the presence of chirp and crosstalk. The results show that a minimal channel spacing of less than 37 and 10 GHz with each channel operating at 2 Gb/s using OOK and FSK, respectively, can be achieved by a dense wavelength division multiple access system. It is also shown that this system performance can be optimized through adjusting various parameters of the laser and the filter.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

High performance interprocessor communication through optical wavelength division multiple access channels

article Free AccessHigh performance interprocessor communication through optical wavelength division multiple access channels Author: Patrick W. Dowd Department of Electrical and Computer Engineering, State University of New York at Buffalo, Buffalo, NY Department of Electrical and Computer Engineering, State University of New York at Buffalo, Buffalo, NYView Profile Authors Info & Claims ACM SIGARCH Computer Architecture NewsVolume 19Issue 3May 1991 pp 96–105https://doi.org/10.1145/115953.115963Published:01 April 1991Publication History 21citation476DownloadsMetricsTotal Citations21Total Downloads476Last 12 Months27Last 6 weeks1 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

Wavelength division multiple access on a high-speed optical fibre LAN

Abstract A multichannel medium access control protocol suitable for implementation on a wavelength division multiplexed optical fibre LAN is discussed. Particular emphasis is placed on the mean delay against network throughput performance at individual channel transmission rates of 100 Mbit/s. The protocol is based on a token passing arbitration policy which dynamically allocates both the token and the data to individual wavelength multiplexed channels. An improved performance is demonstrated in comparison with alternative conventional approaches operating at an equivalent overall network transmission rate.

Crosstalk analysis and filter optimization of single- and double-cavity Fabry-Perot filters

Since Fabry-Perot (FP) filters are major candidates for use as demultiplexers in wavelength division multiple access (WDMA) networks, the authors have analyzed, in an exact and unified manner, the crosstalk degradation for several different variations of the basic FP filter, compared their performances, and optimized their design parameters. A description is given of the system model (a wavelength division multiple access system consisting of M connected transmitters and receivers with each transmitter consisting of an on-off modulated fixed-frequency laser, with the 'off' power level equal to zero) and the parameters used throughout, along with a brief discussion of relevant Fabry-Perot equations and terms and the four different filter structures analyzed. The crosstalk is examined for the cases of a single-cavity FP filter, a double-pass FP filter, a two-stage double-cavity FP filter, and a vernier double-cavity FP filter. The criteria for the performance comparison were the worst-case crosstalk, BER, and crosstalk power penalty.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Passively temperature-compensated fibre Fabry–Perot filter and its application in wavelength division multiple access computer network

Tunable fibre Fabry–Perot filters were constructed and tested to meet the optical and mechanical requirements for a direct detection, passive optical wavelength division multiple access (WDMA) computer network to interconnect computer work stations.

A wavelength division multiple access network for computer communication

A first-generation design, called Rainbow, for optical wavelength division multiaccess (WDMA) computer networks is described. The Rainbow research prototype takes the form of a direct detection, circuit-switched metropolitan-area-network (MAN) backbone consisting of 32 IBM PD/2's as gateway stations, communicating with each other at 200-Mb/s data rates and submillisecond switching times. The prototype architectural options for realizing WDMA networks are discussed, along with reasons for choosing this design point. Experimental measurements on the prototype are presented. Ways of extending this prototype to more stations, higher bit rates, and faster setup times are given.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

High-capacity lightwave local are networks

The author presents an overview of fundamental considerations that guide and motivate research in this area. He explores the relationship between the bandwidth of the fiber, the available power and the loss in various network designs, and the throughput of networks as limited by the medium-access techniques and control mechanisms. He discusses two approaches to opening up the bottleneck that seem particularly promising. The first, multihop, uses a novel network architecture to achieve high capacity with existing devices; the second, wavelength division multiple access (WDMA), emphasizes new devices in a relatively conventional architecture. Noting that the primary disadvantage of the bus topology, poor energy efficiency, could be overcome with a suitable optical amplifier to compensate for the high signal attenuation in the network, the author discusses one of the most promising candidates, the traveling-wave semiconductor amplifier. He also discusses medium-access considerations.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>