A Quasi-Static Optoelectronic ATM Switch

近十年来，光纤几乎无限的带宽使数据传输速度得到了极大的提高，从而催生了远程学习、视频会议等Gb/s级高要求的多媒体业务。ATM作为传输宽带综合业务数字网（BISDN）应用的一种有前途的高效技术已被ITU-T认可。新的挑战在于部署Tb/s组播ATM交换机以满足多媒体和互联网流量的指数级增长。基于路径交换的概念，他们提出了一种Tb/多播ATM交换架构，该架构将电子交换模块与准静态控制光互连网络（OIN）互连。OIN中的路由是预先确定的，以避免逐槽处理，并在虚拟路径级别上提供灵活的交换能力。外围电子交换模块支持组播、快速动态路由和统计复用，以补偿OIN中的准静态路由，达到1 Tb/s的交换容量。这种准静态交换架构将Tb/s ATM交换机的设计简化为具有特色的Gb/s交换模块：电子组播输入输出模块和光中心互连，这些模块在现有技术下都是可行的。未来的研究计划包括三个方面。首先，研究人员将开发一种更新机制，以调整中期路线模式以适应交通变化。将研究时间复杂度和性能之间的权衡。其次，他们将根据我们提出的OIN识别光器件的需求，以有效控制串扰和功率预算。此外，他们将研究在多播电子交换模块中执行输出争用解决的几种方法：为每种方法制定经济有效的设计，从吞吐量，单元延迟和损失率方面研究性能，最终确定具有高性能和合理结构复杂性的最佳方法。

The virtually unlimited bandwidth of optical fibers has caused tremendous increase in data transmission speed during the past decade, thereby stimulating high demanding Gb/s multimedia services such as distance learning and video conferencing. ATM has been accepted by ITU-T as a promising and efficient technique of transporting Broadband Integrated Services Digital Network (BISDN) applications. The new challenge lies in the deployment of Tb/s multicast ATM switches tomeet the exponential growth of multimedia and internet traffic.Based on the concept of the researcher's path switching, they propose a Tb/smulticast ATM switch architecture that interconnects electronic switch modules with a quasi-static controlled optical interconnection network (OIN). Routing in the OIN is predetermined to avoid slot-by-slot processing and to provide flexible switching capacity on virtual pathlevel. The surrounding electronic switch modules support multicasting, fast dynamic routing and statistical multiplexing to compensate the the quasi-static routing in the OIN to achieve totally a Tb/s switching capacity. This quasi-static switching architecture simplifies the design of a Tb/s ATM switch to specially featured Gb/s switch modules: the electronic multicast input and output modules and optical central interconnection, which are all feasible with existing technology.The future research plan includes three aspects. First, the researchers will develop an updating mechanism for readjusting the middle-stage route pattern to adapt the traffic change. The tradeoff between time complexity and performance will be investigated. Secondly, they will identify the requirement of the optical devices to effectively control the crosstalk and the power budget based on our proposed OIN. Inaddition, they will investigate several approaches of performing output contention resolution within multicast electronic switch modules: work out a cost-effective design for each approach, study the performance in terms of throughput, cell delay and loss rate, and finally identify the best approach that has high performance and reasonable construction complexity.