Reconfigurable Optical Bus and Performance Optimization

With the advent of optical fiber and other advanced technologies in solid state,pipelining signals at the wire(or transmission line)level has becomr possible.This has,in turn,made the slotted bus a potential candidate for interconnection networks(IN)for tightly coupled multiprocessor systems.However,a bus an provide only limited bandwidth.Though slotted bus can provide considerably more bandwith in comparison to the traditional non-slotted bus,it is not enough for fine-grain parallel applications run on the shared-memory systems.One well known method to increase the effective bandwidth of a slotted bus in the LAN/MAN environment is to reuse the bandwwidth by reusing slots.However,in a tightly coupled environment reusing slots is not a lucrative option because the significant buffering needs arising from slot reuse will introduce intolerable delay.In this paper we propose a methodology to reuse part of the bandwith available from temporal and spectral bandwidth expansion with none of minimum buffering delay,resulting in significant performance improvement in both the effective throughput and response time(communication latency).The proposed method entails the design and analysis of a re-configurable bus structure with both temporal and spectral bandwidth expansion and a polynomial time algorithm for optimal configurations for given traffic conditionslWe have compared the performance of our reconfigured bus with that of the traditional slotted bus for uniform and localized traffic pattern and founr that the reconfigured bus outperforms the traditional slotted bus substantially in many practical scenarios.