Multilevel broadcast recipient maximization in IEEE 802.16j using ant colony optimization

IEEE 802.16j supports WiMAX in extending the service area of Base Stations (BSs) through Relay Stations (RSs) for serving more Subscriber Stations (SSs). Effective allocation of resources is key to maximize the number of served SSs for the downlink broadcast service in IEEE 802.16j WiMAX relay network. Most existing studies concentrate on the single-level relay network where the BS sends data to the SS through at most one RS. This study focuses on the multilevel broadcast recipient maximization (ML-BRM) problem, in which RSs are particularly allowed to relay data from other RSs. To address this problem, we propose a MAX-MIN ant system (MMAS) and use the information of single-source shortest path tree to improve solution quality. Simulation results validate the effectiveness of the proposed method in comparison with state-of-the-art algorithms.