On the benefits of traffic bifurcation in multi-granular optical transport networks

The multi-granular optical transport network is expected to be the ¿future-proof¿ solution for mitigating the Optical Crossconnect (OXC)/Reconfigurable Optical Add and Drop Multiplexers (ROADM) scalability problems associated with the continuing growth of traffic in optical transport networks. Although the multi-granular optical network promises exciting opportunities, it also presents new design challenges that have been the focus of research and development in this area. The major challenges stem from the need to perform the following tasks efficiently: (1) determining the route and assigning colors to wavelength-, waveband-, and fiber-switched paths; and (2) grouping/degrouping sub-wavelength-switched paths into/from wavelengths, wavelength-switched paths into/from wavebands, and waveband-switched paths into/ from fibers. In this paper, we explore the benefits of incorporating the demand-bifurcation feature into the design and planning process of the multi-granular optical network. Our extensive simulation results demonstrate that the bifurcation of demands can be beneficial under certain conditions.