A GRASP algorithm with RNN based local search for designing a WAN access network

The Greedy Randomized Adaptive Search Procedure (GRASP) is a well-known metaheuristic for combinatorial optimization. In this work, we introduce a GRASP for designing the access network topology of a Wide Area Network (WAN). This problem is NP-hard, and can modeled as a variant of the Steiner Problem in Graphs. oposed GRASP employs a Random Neural Network (RNN) model in the local search phase, in order to improve the solutions delivered by the construction phase, based on a randomized version of the Takahashi-Matsuyama algorithm. Experimental results were obtained on 155 problem instances of different topological characteristics, generated using the problem classes in the SteinLib repository, and with known lower bounds for their optima. The algorithm obtained good results, with low average gaps with respect to the lower bounds in most of the problem classes, and attaining the optimum in 40 cases (more than 25% of the problem set).