Fuzzy priority based overlay multicast

Among the existing overlay multicast protocols, the Priority-based directed minimum Spanning Tree (PST) is designed for Distributed Interactive Applications (DIAs), and it uses priority to quantify the relationship between two nodes and guarantees the nodes with high priority receiving data in a short delay. Since the priority is calculated only from the distance between the nodes’ avatars, and the available bandwidth (avail-bw) of nodes is not considered in multicast tree building, PST cannot use avail-bw efficiently and in some cases the priority might be calculated inaccurately. In this paper we propose a novel overlay multicast protocol named Fuzzy priority based Overlay Multicast (FOM), which adopts a fuzzy mechanism to accurately calculate the priority by taking all the attributes of avatars into consideration, and utilizes priority, delay, and avail-bw synthetically to build multicast trees. When avail-bw is insufficient to build a multicast tree, a priority based filtering mechanism is implemented to rebuild it. The simulation results show that with group number and observation region increasing, FOM has the best performance on tree build rates, mean relative delay penalty, and mean bandwidth usage percentage, and it is more suitable for DIAs than protocols ALMI and PST.