Resource Management and Optimization in Future Optical Networks.

详细信息   

• 作者：Wang ; Rui.
• 学历：Doctor
• 年：2014
• 毕业院校：University of California
• Department：Computer Science.
• ISBN：9781321213232
• CBH：3637919
• Country：USA
• 语种：English
• FileSize：28967652
• Pages：123

文摘

Optical networks are playing an increasingly vital role in scaling up the speed of todays Internet. Wavelength-division multiplexed WDM) networks traditionally have been expanding capacity by increasing the number of wavelengths and the line rate of each wavelength. Because each wavelength is restricted within a fixed-size spectrum grid,usually 50 GHz,this scaling model has reached a bottleneck. Specifically,the 50-GHz grid cannot accommodate line rates beyond 100 Gb/s. A more flexible wavelength model emerged a few years ago,where each wavelength is allocated a variable-size grid. This is also known as Flexgrid. The size of the allocated spectrum is tailored according to the needs of the optical channel. Higher-bit-rate and longer-distance channels are assigned a larger spectrum. However,this flexibility does not come for free. With optical channels now taking up sometimes vastly) different spectrum footprints,the spectrum management becomes more challenging. We devote the first half of this dissertation to address the problem of spectrum fragmentation that arises in this context. We first quantify this phenomenon,and then develop preventive and remedial methods to eliminate or alleviate the impacts of fragmentation on service provisioning. In optical access networks,WDM technology has been gradually adopted to scale up the bandwidth. Time- and wavelength-division multiplexed passive optical network TWDM-PON) has evolved from the pure TDM-PON architecture. Each wavelength is shared in a TDM fashion by multiple optical network units ONUs). To dynamically adapt this sharing relationship,i.e.,which ONUs share which wavelength,according to the changing traffic,we develop mathematical models and heuristic algorithms that together form a comprehensive solution for both the planning and operational stages. The solution optimizes energy usage while maintaining quality-of-service QoS) requirements. WDM technology also finds an unlikely application in avionic systems. We propose and design a specialized WDM ring architecture,named AVATAR,to replace the dated copper-based communication infrastructure in todays avionic systems. AVATAR leverages multi-wavelength and spatial reuse properties of a WDM ring through sophisticated packet scheduling. With careful optimization,a base-line,two-wavelength configured AVATAR can achieve a significant performance margin over conventional architectures.