The inherent selfishness of each node for the enhancement of message successful delivery ratio and the network overall performance improvement are reflected in the contradiction relationship of competition and cooperation in delay/disruption tolerant networks (DTN). In particular, the existence of malicious node aggravates this contradiction. To resolve this contradiction, social relationship theory and group theory of social psychology were adopted to do an in-depth analysis. The concrete balancing approach which leveraged Nash equilibrium theory of game theory was proposed to resolve this contradiction in reality. Thus, a new congestion control routing algorithm for security defense based on social psychology and game theory (CRSG) was put forward. Through the experiment, this algorithm proves that it can enhance the message successful delivery ratio by more than 15% and reduce the congestion ratio over 15% as well. This algorithm balances the contradiction relationship between the two key performance targets and made all nodes exhibit strong cooperation relationship in DTN.
空间网络拓扑持续动态变化、节点资源受限等特点,致使地面路由协议难以直接应用于空间网络.本文结合空间网络的特点,借鉴地面网络的路由机制,设计并实现了一种通用型预置空间路由协议——PSRP(Presetting Space Routing Protocol).PSRP协议是一种动静结合的自适应空间路由协议,其主要思想是:充分利用空间网络拓扑变化的可预知性,预先将拓扑变化的时机和对应的路由信息保存在各节点上,并依据拓扑变化的时机切换路由表,在网络发生异常时能及时更新各节点保存的路由相关信息.实验仿真证明,PSRP在网络正常运行时因可以省去网络拓扑变化引起的路由收敛和重分布过程,从而大大提高了链路利用率,降低了报文丢包率,节省了报文交互开销.
In recent years,using message ferries as mechanical carriers of data has been shown to be an effective way to collect information in sparse wireless sensor networks.As the sensors are far away from each other in such highly partitioned scenario,a message ferry needs to travel a long route to access all the sensors and carry the data collected from the sensors to the sink.Typically,practical constraints(e.g.,the energy)preclude a ferry from visiting all sensors in a single tour.In such case,the ferry can only access part of the sensors in each tour and move back to the sink to get the energy refilled.So,the energy-constrained ferry route design(ECFRD)problem is discussed,which leads to the optimization problem of minimizing the total route length of the ferry,while keeping the route length of each tour below a given constraint.The ECFRD problem is proved to be NP-hard problem,and the integer linear programming(ILP)formulation is given.After that,efficient heuristic algorithms are proposed to solve this problem.The experimental results show that the performances of the proposed algorithms are effective in practice compared to the optimal solution.
