Cost-effective heuristics for planning GMPLS-based transport networks

With the ever-increasing traffic in WDM transport networks, the development of GMPLS (or multi-granular) transport networks becomes essential to avoid the cost explosion of OXCs. Much work has been devoted to the development of Multi-Granular Optical Crossconnect (MG-OXC) architectures and network design and planning methods. Extending these efforts here, we address a new problem of planning the GMPLS-based transport network by (1) considering the whole traffic hierarchy defined in GMPLS; and (2) allowing the bifurcation of multi-granularity traffic demands among different physical routes. We call such a problem the Routing and Multi-Granular Paths Assignment (RMGPA). The objective of the problem is to minimize the total weighted port count in the transport network. Due to the computational complexity of the problem, only very small-sized planning problems can be solved exactly through Mixed Integer Linear Programming (MILP) optimization. In this paper, we propose efficient heuristics that are capable of solving large-sized planning problems in a reasonable amount of time.