Minimizing ADMs on WDM directed fiber trees

This paper proposes a polynomial-time algorithm for Minimum WDM/SONET Add/Drop Multiplexer Problem (MADM) on WDM directed fiber trees whether or not wavelength converters are used. It runs in time O(m2n), where n and m are the number of nodes of the tree and the number of the requests respectively. Incorporating T. Erlebach et al.'s work into the proposed algorithm, it also reaches the lower bound of the required wavelengths with greedy algorithms for the case without wavelength converters. Combined with some previous work, the algorithm reduces the number of required wavelengths greatly while using minimal number of ADMs for the case with limited wavelength converters. The experimental results show the minimal number of required ADMs on WDM directed fiber trees.