A novel design of optical cross-connects with multi-granularity provisioning support for the next-generation Internet

This paper proposes a scalable design for next-generation optical cross-connects (OXCs), where a novel strategy for dimensioning the network switching capability as a long term planning is presented. When traffic demand grows, the proposed scheme simply expands the switching capacity of OXCs in waveband- and fiber-switching tiers. To minimize the number of extra fibers for waveband- and fiber-switching tiers required to satisfy a given traffic matrix, we formulate the problem of routing and wavelength assignment with tunnel allocation (RWAT) into two integer linear programming (ILP) processes that are performed sequentially. Experiments are conducted on two sample networks to compare the throughput and the number of switch points when the networks adopt different switching architectures with different traffic loads. We conclude that the proposed optimization scheme can dimension the networks with expandability and scalability to the growing traffic demand.