Network planning algorithms for the optical Internet based on the generalized MPLS architecture

GMPLS is one of the most promising frameworks proposed for the next generation optical Internet, which supports multi-granularity of switching types including fiber-, waveband- and lambda-switching in the optical domain. We present some algorithms for solving the routing and wavelength/tunnel assignment (RWTA) problem based on the multi-granularity 4-tier switching architecture. We also propose novel network planning algorithms, the weighted network link state, and an enhancement to the fixed-alternative routing scheme, the heavy fixed alternative routing (H-FAR), to facilitate RWTA. We show that with the weighted network link state and H-FAR, the RWTA problem in the optical Internet with multi-granularity OXCs (MG-OXCs) can be solved efficiently, and the performance in terms of call blocking rate in a network with MG-OXCs is comparable with that in a lambda-switched network, which means the link utilization of tunnels is close to that of wavelength-switched channels