DP_DCLC: A New Algorithm for Delay-bounded Constraint Multicast Routin

In multicast routing, the key of building a minimum cost multicast tree is the constrained minimum Steiner tree (CMST). Bounded shortest path algorithm (BSMA) is the most famous algorithm for CMST problem. But using the K-th shortest path (KSP) algorithm to find the delay-constrained least-cost (DCLC) path needs high time complexity. LR DCLC is an approximate algorithm based on Lagrange relaxation for the DCLC problem, but such approximate algorithm cannot find the optimal path. In this paper, an exact dynamic programming algorithm DP DCLC for DCLC path is proposed, which can efficiently reduce the time complexity of BSMA and can meet the QoS routing requirements. We compare the DP DCLC´s performance with KSP and LR DCLC algorithms through the random graph model (RGM) in C⁺⁺ code. The simulation results show that DP DCLC can bulid the delay constraint path with minimum cost, and can outperform KSP and LR DCLC in the CT (cost multiply time) index.