Scaling optical networks using full-spectrum spatial switching

Accommodating sustained exponential traffic growth in optical networks requires scaling the spatial dimension using space-division multiplexing. Numerous uncoupled spatial channels may be realized by activating multiple parallel fibers or cores in multicore fibers. A multiplicity of uncoupled spatial channels will render the granularity provided by multiple wavelength channels less essential in enabling optical switching. In this paper, we investigate a possible paradigm shift in optical node architectures, in which nodes based on wavelength-selective switching are replaced by those based on simple spatial switching. We compare spatial switching of full-spectrum superchannels to wavelength switching of uncoupled spatial superchannels, considering the evolution of traffic over time. Our results show that spatial switching may achieve more efficient scaling than wavelength switching in roughly 10 to 17 years, depending on the traffic growth rate assumed.