| Summary: | 博士 === 國立臺灣大學 === 電機工程學研究所 === 92 === The diffusion of Internet traffic, IP-based networks, and applications is growing at an exponential rate in both private and public networks while IP is becoming the dominant protocol for information communication technology. Thus, IP over WDM has become a very important area of study. Accompanied with the advent of multimedia services such as distributed data processing, broadcasting systems, teleconferencing, and bandwidth-on-demand applications, WDM on Next Generation Internet (NGI) need to provide all-optical transmission efficiently.
First, A new media access control (MAC) protocol is proposed to overcome the disadvantages of TDMA and retain its advantages. Various network topologies, such as bus, ring and star, as well as WDM (Wavelength division multiplexing) and TDMA (Time Division Multiplexing Access) are popular in MAN/LAN. On the other hand, the network traffic in these applications such as multimedia, videoconferencing, etc., usually exhibits traffic locality. As a result, traditional TDMA is no longer appropriate for such traffic because of inefficiency. Consequently, based on the traffic parameters such as locality and loading, an architecture named as rGDBLN (r Group Dual Bus Lightwave Network), which partitions/reconfigures the network into several control groups, is proposed. Furthermore, the interleaved control slot (ICS) equipped with cross-group section (CGS) and non-cross-group section (NCGS) for reducing collisions is also presented. The slot reuse can be easily achieved by using the ICS scheme and the slot utilization of the network is superior to the original network under the specific traffic.
Then we propose a series of multicasting and fault-tolerant optical crossconnect (MFOXC) architecture that can support multicasting and fault tolerance. First, a tap-based and two splitter-based MFOXC node architectures are presented for wavelength routed all-optical networks. Compared to the traditional optical crossconnect, the proposed MFOXC node not only has the advantage of multicast capability but also improves the capability of fault tolerance. It could be assigned to critical point in networks to improve the reliability and multicast performance. Furthermore, the communication patterns considered in our algorithms include three general types covering almost all current communication patterns. The MFOXC routing algorithms for point-to-point, multicast and multiple multicasts are presented. We also propose a fault model that is more complete than the existing ones by considering both the active and passive faults. In addition to the fault model, a corresponding restoration mechanism is also proposed. On the other hand, the impact on network reliability and cost of the development of the optical networking are an active area of investigation. We also propose a reliability modeling to evaluate the multicasting and fault-tolerant optical crossconnect (MFOXC) structures and compare them in terms of reliability and cost sensitivity. The probability of error-free operations has been investigated for both MFOXC architectures. We present our evaluation results with a commonly used reliability measure, the mean time between failures (MTBF). Finally, we propose the cost and sensitivity analysis for these MFOXC structures. The cost model and the sensitivity analysis show that the cost reduction in different components has various impacts on the total cost of a MFOXC architecture. It can help us to know which component dominates the total cost and how to make a decision to choose among different MFOXC structures.
Finally, we analyze and design of a Backbone Architecture with TDMA Mechanism for IP Optical Networking. We propose a new technique for constructing IP over photonic systems. The use of label switching is assumed in the IP routers, while a new routing architecture is introduced to transport IP packets across an optical backbone network. The architecture is based on a two-level TDMA structure with wavelength division multiplexing (WDM). Furthermore, we propose an analytical model and evaluate the network performance by comparing the relationship between the slot utilization and the number of groups. In order to evaluate the effectiveness of the technique, we introduce an analytical model allowing us to calculate the IP packet loss probability . We also model the technique by means of a Markovian process whose state is constituted by two discrete variables. The results of analytical model show that the performance of network depends on the network loading, locality, and number of groups Hence, if a system can be operated with appropriate loading, grouping, and traffic locality, its utilization and throughput will be expanded.
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