机会网络以存储-携带-转发的方式实现节点间通信,高效的节点缓存管理策略能够充分利用有限的缓存空间。该文提出了一种基于消息冗余度动态估计的自适应缓存管理机制,利用消息携带节点的活跃程度和当前网络状态下消息副本数量,预测给定消息的投递状态,节点以消息冗余程度为参数确定消息的转发以及携带优先级。结果表明,所提出的节点活跃度和消息副本数的估计方法比较准确,同时所提出的缓存管理策略能有效提高消息成功投递率,降低网络平均时延和网络负载率。
With the manner of storing-carrying-forwarding,nodes can communicate with each other in opportunistic network,but the limited buffer should be used reasonably.Based on message redundancy estimating,an adaptive buffer management mechanism is proposed in this paper.According to the node's activity degree and the number of message copies,the status of message transmitting in the network can be predicted;moreover,with the parameter of message redundancy,the decision on message receiving and forwarding can be made dynamically.Numerical results show that the methods to evaluate node's activity degree and number of message copies are accurate;furthermore,comparing with other buffer management mechanisms,the proposed mechanism can improve message delivery rate effectively,reduce latency and overhead ratio.