A Generalized Approach to WDM Optical Switched Networks

摘要：WDM光分组交换网络的一种通用方法：第三代“全光”网络被提倡通过绕过电子设备的速度限制，使容量增加近4个数量级。在光分组交换网络中，需要有一种方法来处理多个分组同时争夺关键光网络资源时出现的基本资源争用问题。这些可以是发射器、接收器、开关和信道。为了实现光纤的光容量，即消除电子瓶颈，必须解决资源争用问题，使数据包在光域中保持网络的畅通。一种可能的解决方案是基于使用光开关和光纤延迟线来实现全光开关，称为交换延迟线（SDL）。该方法的优点包括相对简单、具有实现潜力和出色的性能。本研究的目标是将上述解决方案扩展到波长敏感开关的情况下，针对新兴的基于WDM的通信环境。初步结果表明，SDL WDM解决方案可以提供：1)光WDM分组交换传输；2)采用基于少量延迟线、最小功能开关、用WDM滤波代替快速可调性的有吸引力的硬件设计；3)容错；4)可行的电子控制。本研究的研究成果有望为下一代光分组交换LAN/MAN WDM网络奠定基础。因此，它将允许在局域网和城域网通信系统中使用WDM，以便将几个高速数据流多路复用到光纤上，而不需要不切实际的并行电子处理。因此，光网络的吞吐量潜力可能会增加几个数量级，为未来的应用铺平道路。

ABSTRACT: Chlamtac, Imrich NCR-9406522 University of Massachusetts A Generalized Approach to WDM Optical Packet Switched Networks: Third generation "all-optical" networks are advocated to yield a nearly four orders of magnitude capacity increase by circumventing the speed limitations of electronics. In an optical packet switched network it is necessary to have a methodology to deal optically with the fundamental resource contentions problem occurring when multiple packets are concurrently vying for key optical network resources. These can be transmitters, receivers, switches, and channels. To realize the optical capacity of the fiber, i.e., eliminate the electronic bottleneck, resource contention must be resolved in a way which maintains packets flowing through the network in the optical domain. One possible solution is based on the use of optical switches and fiber delay lines to realize an all-optical switch termed Switched Delay Lines (SDL). Among the advantages demonstrated for this approach are its relative simplicity, implementation potential and excellent performance. The goal of this research is the extension of the above solution to the case of wavelength sensitive switches, targeted towards the emerging WDM based communications environment. Preliminary results show that an SDL WDM solution can offer: 1) an optical WDM packet switching transmission; 2) use of attractive hardware design based on small number of delay lines, minimal functionality switches, replacement of fast tunability by WDM filtering; 3) fault tolerance; and 4) feasible electronic control. The research results of this study can be expected to lay a basis for the next generation optical packet switched LAN/MAN WDM networks. It will thus enable the use of WDM in LAN and MAN communication systems for multiplexing several high speed data streams onto the optical fiber, without requiring unrealistic parallel electronic processing. As a result, the throughput potential of optical networks may be increased by orders of magnitude paving the way for future applications.