Optical fiber busses supporting multiple concurrently usable channels through the use of wavelength division multiplexing can meet the demanding interconnection requirements of high performance multiprocessors. Using a simple analytical model, we establish why global channel access protocols for the WDM channels are inadequate for a WDM optical fiber bus. We propose a simple WDM bus that supports a small number of channels and uses readily available receivers and transmitters with fixed tunings. A simple channel allocation and arbitration strategy allows up to 100 processors to be connected using a single WDM bus with only 5 WDM channels. Simulated performance shows that the bus does not become a bottleneck even when 100 processors are connected. The WDM channels also allow cache coherence and processor synchronization to be easily supported, making the bus feature- compatible with the IEEE Futurebus+ and SCI standards.
"Performance potentials of an optical bus using wavelength-division multiplexing", Proc. SPIE 1849, Optoelectronic Interconnects, (1 July 1993); doi: 10.1117/12.147092; https://doi.org/10.1117/12.147092