Mobile opportunistic network(MON)is an efficient way of communication when there is no persistent connection between nodes.Multicast in MONs can be used to efficiently deliver messages to multiple destination nodes.Ho...Mobile opportunistic network(MON)is an efficient way of communication when there is no persistent connection between nodes.Multicast in MONs can be used to efficiently deliver messages to multiple destination nodes.However,because multiple destination nodes are involved,multicast routing is more complex than unicast and brings a higher communication cost.Backbone-based routing can effectively reduce the network overhead and the complexity of routing scheme.However,the load of backbone nodes is larger than that of regular nodes.If the backbone node’s buffer is exhausted,it will have a significant impact on the performance of the routing scheme.Load balancing can improve the ability of backbone to deal with the change of network load,and backbone maintenance algorithm can provide backbone robustness.In this paper,we propose a robust load-balanced backbone-based multicast routing scheme in MONs.In the backbone construction algorithm,we transform the problem of backbone construction into a multi-objective optimization problem,and propose a multi-objective evolutionary algorithmbased backbone construction algorithm,namely LBMBCMOEA algorithm.In addition,in order to increase the robustness of the backbone-based routing scheme,we propose a localized multicast backbone maintenance algorithm(MBMA)to deal with the buffer exhaustion of backbone nodes.When a backbone node’s residual buffer is insufficient,MBMA algorithm selects other nodes to replace the backbone node.The results on extensive simulations show that when considering the node buffer size constraints,compared with previous backbone-based multicast routing schemes,our proposed algorithm has better performance,and when the node’s residual buffer is insufficient,MBMA algorithm can significantly improve the performance of the backbone-based multicast routing scheme.展开更多
The multimedia conferencing system is an important tool for Computer supported Cooperative Work (CSCW), and also one of the basic techniques supporting team work in the Concurrent Engineering. In this paper the archit...The multimedia conferencing system is an important tool for Computer supported Cooperative Work (CSCW), and also one of the basic techniques supporting team work in the Concurrent Engineering. In this paper the architecture and function modules of the reported multimedia conferencing system are described. Then in order to reduce the network bandwidth required by the conferencing system, two methods for sending the conferencing data by using multicasting are discussed.展开更多
基金supported in part by the National Natural Science Foundation of China(Grant Nos.61972044 and 61732017)the Fundamental Research Funds through the Central Universities(2020XDA09-3)+1 种基金the Funds for International Cooperation and Exchange of NSFC(Grant No.61720106007)the 111 Project(B18008).
文摘Mobile opportunistic network(MON)is an efficient way of communication when there is no persistent connection between nodes.Multicast in MONs can be used to efficiently deliver messages to multiple destination nodes.However,because multiple destination nodes are involved,multicast routing is more complex than unicast and brings a higher communication cost.Backbone-based routing can effectively reduce the network overhead and the complexity of routing scheme.However,the load of backbone nodes is larger than that of regular nodes.If the backbone node’s buffer is exhausted,it will have a significant impact on the performance of the routing scheme.Load balancing can improve the ability of backbone to deal with the change of network load,and backbone maintenance algorithm can provide backbone robustness.In this paper,we propose a robust load-balanced backbone-based multicast routing scheme in MONs.In the backbone construction algorithm,we transform the problem of backbone construction into a multi-objective optimization problem,and propose a multi-objective evolutionary algorithmbased backbone construction algorithm,namely LBMBCMOEA algorithm.In addition,in order to increase the robustness of the backbone-based routing scheme,we propose a localized multicast backbone maintenance algorithm(MBMA)to deal with the buffer exhaustion of backbone nodes.When a backbone node’s residual buffer is insufficient,MBMA algorithm selects other nodes to replace the backbone node.The results on extensive simulations show that when considering the node buffer size constraints,compared with previous backbone-based multicast routing schemes,our proposed algorithm has better performance,and when the node’s residual buffer is insufficient,MBMA algorithm can significantly improve the performance of the backbone-based multicast routing scheme.
文摘The multimedia conferencing system is an important tool for Computer supported Cooperative Work (CSCW), and also one of the basic techniques supporting team work in the Concurrent Engineering. In this paper the architecture and function modules of the reported multimedia conferencing system are described. Then in order to reduce the network bandwidth required by the conferencing system, two methods for sending the conferencing data by using multicasting are discussed.
