A Distributed Asynchronous Transmission Access Strategy for Optical Single-Hop LANs: An Analytical Performance Study

In this paper, we introduce an optical passive network architecture suitable for wavelength division multiplexing local area networks (LANs) which use a separate control wavelength. The data wavelengths are organized into several sets, while the access rights over them are distributedly determined aiming to totally expunge the packets collisions on the wavelengths and at destination. The proposed access algorithm pertains to the asynchronous transmission schemes. Thus, it is simple enough since it does not require any synchronization among the stations, providing high efficiency especially under high data rates (100 Gbps and beyond). The performance is evaluated through exhaustive analysis, whilst closed mathematical formulas provide the performance measures. The comparative study proves that the proposed wavelengths organization into sets strategy along with the access scheme significantly improves the performance. Especially, the throughput improvement is proven to be higher as the number of sets increases, and more than 100% even by organizing the wavelengths into only two sets, for diverse numbers of data wavelengths, data wavelengths sets and data packets size. Finally, the proposed study could be applied to optical passive single-hop LANs such as intra-rack data center networks or local institutional or enterprise networks

Wavelength and time division multiplexing with lightpath trespassing for all-optical star local area networks

Many medium access control protocols have been proposed for optical wavelength division multiplexing local area networks with a star topology. These protocols range from those based on the concept of fixed-assignment of communication subchannels, such as TDMA (Time Division Multiple Access); reservation of communication subchannels, such as DAS (Dynamic Allocation Scheme); or random-access to communication subchannels, such as DT-WDMA (Dynamic Time-Wavelength Division Multiple Access). In addition various hybrid protocols have been considered, for example, protocols incorporating both fixed-assignment and reservation rules, such as HTDM (Hybrid TDM). This thesis is on a novel hybrid protocol of fixed-assignment and random-access called "WTDMA with lightpath trespassing". This protocol combines the most desirable aspects of fixed-assignment and random-access protocols, while limiting their drawbacks. The performance of different versions of the protocol are analysed both mathematically and by stochastic simulation. The obtained results justify the introduction of the WTDMA with trespassing protocol, and indicate the situations where its use is advantageous

Transient Analysis of Photonic Networks

The behavior of slotted aloha protocol for a star-coupled Wavelength Division Multiple Access (WDMA) photonic network is studied. Semi-markov process is used for developing the steady state and transient models for the protocol. The performance of the network is evaluated in terms of various measures viz. average number of packets in the network, throughput of the network and average packet delay etc. The analytical models are validated by evaluating the numerical values of the performance indices, which are further compared by using Adaptive Neuro Fuzzy Inference System (ANFIS) approach. Keywords:Photonic networks, Slotted aloha, Semi-markov process, Neuro-fuzzy systems, Throughput.

Application of new electro-optic technology to Space Station Freedom data management system

A low risk design methodology to permit the local bus structures to support increased data carrying capacities and to speed messages and data flow between nodes or stations on the Space Station Freedom Data Management System in anticipation of growing requirements was evaluated and recommended. The recommended design employs a collateral fiber optic technique that follows a NATO avionic standard that is developed, tested, and available. Application of this process will permit a potential 25 fold increase in data transfer performance on the local wire bus network with a fiber optic network, maintaining the functionality of the low-speed bus and supporting all of the redundant transmission and fault detection capabilities designed into the existing system. The application of wavelength division multiplexing (WDM) technology to both the local data bus and global data bus segments of the Data Management System to support anticipated additional highspeed data transmission requirements was also examined. Techniques were examined to provide a dual wavelength implementation of the fiber optic collateral networks. This dual wavelength implementation would permit each local bus to support two simultaneous high-speed transfers on the same fiber optic bus structure and operate within the limits of the existing protocol standard. A second WDM study examined the use of spectral sliced technology to provide a fourfold increase in the Fiber Distributed Data Interface (FDDI) global bus networks without requiring modifications to the existing installed cable plant. Computer simulations presented indicated that this data rate improvement can be achieved with commercially available optical components

Channel-tunable mode-locked laser transmitter for OTDM networks and modeling of mode-locked semiconductor laser.

by Hung Wai.Thesis (M.Phil.)--Chinese University of Hong Kong, 2000.Includes bibliographical references (leaves 69-[73]).Abstracts in English and Chinese.Chapter 1 --- Introduction --- p.1Chapter 1.1 --- All Optical Multi-Access Network --- p.1Chapter 1.2 --- Multi-access Techniques --- p.2Chapter 1.2.1 --- Wavelength-Division Multi-access (WDMA) --- p.2Chapter 1.2.2 --- Subcarrier Multi-Access (SCMA) --- p.3Chapter 1.2.3 --- Time-Division Multi-Access(TDMA) --- p.3Chapter 1.3 --- Numerical Modelling of Semiconductor Mode-locked laser --- p.4Chapter 1.4 --- Objective of this Thesis --- p.5Chapter 2 --- Optical TDMA networks --- p.7Chapter 2.1 --- Introduction --- p.7Chapter 2.2 --- OTDM --- p.8Chapter 2.3 --- Network Architecture --- p.9Chapter 2.3.1 --- Broadcast Networks --- p.9Chapter 2.3.2 --- Switch-based networks --- p.10Chapter 2.4 --- Key technologies for optical TDMA Network --- p.13Chapter 2.4.1 --- High Repetition Rate Short Pulse sources --- p.13Chapter 2.4.2 --- Multiplexer and de-multiplexers --- p.15Chapter 2.4.3 --- Optical Clock Recovery --- p.17Chapter 2.4.4 --- All optical logic gates --- p.18Chapter 2.5 --- Summary --- p.19Chapter 3 --- A Channel-Tunable Mode-locked Laser Transmitter for OTDM Networks --- p.20Chapter 3.1 --- Introduction --- p.20Chapter 3.2 --- Principle of Operation --- p.21Chapter 3.3 --- Experimental Demonstration --- p.23Chapter 3.4 --- The Channel Tuning Transient --- p.25Chapter 3.5 --- Experimental Investigation of channel-tuning transient --- p.28Chapter 3.6 --- Summary --- p.37Chapter 4 --- Modeling of Mode-Locked Semiconductor Laser --- p.38Chapter 4.1 --- Introduction --- p.38Chapter 4.2 --- Principle of Mode-Locking --- p.39Chapter 4.3 --- Simulation Model --- p.41Chapter 4.3.1 --- Travelling Wave Rate Equation Analysis --- p.41Chapter 4.3.2 --- Large Signal Time Domain Mode-locked Laser Model --- p.42Chapter 4.3.3 --- Modeling of Spontaneous Noise --- p.44Chapter 4.3.4 --- Modeling of Self-phase Modulation --- p.44Chapter 4.3.5 --- Frequency Dependent Gain Profile --- p.45Chapter 4.3.6 --- Computation Procedure --- p.45Chapter 4.4 --- Device Parameters --- p.47Chapter 4.5 --- Simulation Results on Passive Mode-locking --- p.48Chapter 4.5.1 --- Pulse Repetition Rate under Passive Mode-locking --- p.48Chapter 4.5.2 --- The effect of Differential Gain and Differential Absorption on Mode-locking Regimes --- p.50Chapter 4.5.3 --- The Effects of Linewidth Enhancement Factor and Ab- sorber Carrier Lifetime on Mode-locking Pulse Width --- p.53Chapter 4.6 --- Simulation Results on Hybrid and Subharmonic Mode-locking --- p.54Chapter 4.6.1 --- Modeling the Effect of Modulation on Absorber Section --- p.54Chapter 4.6.2 --- Modulation Phase Change Dynamics --- p.55Chapter 4.6.3 --- Subharmonc Mode-Locking Induced Amplitude Modulation --- p.62Chapter 4.7 --- Summary --- p.64Chapter 5 --- Conclusion --- p.66Chapter 5.1 --- Summary of the Thesis --- p.66Chapter 5.2 --- Future Work --- p.67Bibliography --- p.6