Discrete bandwidth allocation considering fairness and transmission load in multicast networks

As a promising solution to tackle the network heterogeneity in multicasting, layered multicast protocols such as receiver-driven layered multicast (RLM) and layered video multicast with retransmission (LVMR) have been proposed. This paper considers fairness as well as transmission load in the layered multicasting. Lexicographically fair bandwidth allocation among multicast receivers is considered under the constraint of minimum bandwidth requirement and the link capacity of the network. The problem of transmission load in the layer multicasting due to various user requirements is also examined by minimizing the number of layers. The bandwidth allocation is formulated as a nonlinear integer programming problem. A dual-objective tabu search is proposed to solve the fairness and transmission load problem in multicast networks. Outstanding performance is obtained by the proposed tabu search. When the fairness objective is considered, the solution gap from the optimal solution is less than 2% in problems with 50 virtual sessions. The complexity of the dual objective largely depends on the weighting factor of the two objectives. Even in tough cases the proposed tabu search provides excellent solution, whose gap is within 6% from the optimal solution.