Low-interference multicast routing in multi-radio multi-channel wireless mesh networks using adaptive directional antennas

This paper deals with the problem of multicast routing in Multi-Radio Multi-Channel Wireless Mesh Networks (MRMC-WMNs) equipped with directional antennas. We jointly consider the wireless broadcast advantage, the directional antenna technology, and the interference-aware path selection metric to improve the network performance. Although using directional antennas reduces the interference, it increases the number of transmissions. The adaptive directional antenna is an effective approach to control this trade-off. In this regard, we propose four cross-layer algorithms named “Directional Transmission aware Multicast Tree (DTMT)”, “Directional Interference-aware Multicast Tree (DIMT)”, “Steerable Beam Multicast routing (SBM)”, and “Interference-aware Steerable Beam Multicast routing (ISBM)”. As an advantage, these algorithms jointly address the problems of multicast tree construction, transmission channel selection, and transmission beam specification. DTMT and DIMT are implemented on three types of graphs called “Random Oriented Graph (ROG)”, “Adaptive Oriented Graph (AOG)”, and “Adaptive beam Graph (ABG)”. AOG and ABG try to find the best sector by steering the directional antennas. Differently, in SBM and ISBM, the beam-width and orientation of each antenna are adaptively characterized during the procedure of the tree construction. Numerical results demonstrate that the proposed algorithms effectively outperform other existing algorithms in terms of the interference and the number of transmissions.