Deep space networks,satellite networks,ad hoc networks,and the Internet can be modeled as DTNs(Delay Tolerant Networks).As a fundamental problem,the maximum flow problem is of vital importance for routing and service ...Deep space networks,satellite networks,ad hoc networks,and the Internet can be modeled as DTNs(Delay Tolerant Networks).As a fundamental problem,the maximum flow problem is of vital importance for routing and service scheduling in networks.However,there exists no permanent end-to-end path since the topology and the characteristics of links are time-variant,resulting in a crucial maximum flow problem in DTNs.In this paper,we focus on the single-source-single-sink maximum flow problem of buffer-limited DTNs,followed by a valid algorithm to solve it.First,the BTAG(Buffer-limited Time Aggregated Graph)is constructed for modeling the buffer-limited DTN.Then,on the basis of BTAG,the two-way cache transfer series and the relevant transfer rules are designed,and thus a BTAG-based maximum flow algorithm is proposed to solve the maximum flow problem in buffer-limited DTNs.Finally,a numerical example is given to demonstrate the effectiveness of the proposed algorithm.展开更多
多层卫星网络的拓扑结构具有明显的时变特征,难以提供持续且稳定的端到端路径,导致高效路由问题面临着巨大的挑战.将卫星网络设计为封闭的体系结构,采用强管理或调度式控制策略会导致其无法自由、高效地实现与其它系统的协同组网.基于I...多层卫星网络的拓扑结构具有明显的时变特征,难以提供持续且稳定的端到端路径,导致高效路由问题面临着巨大的挑战.将卫星网络设计为封闭的体系结构,采用强管理或调度式控制策略会导致其无法自由、高效地实现与其它系统的协同组网.基于IP的网络体系结构在应用于多层卫星网络时又存在路由效率不高的问题.基于命名数据网络NDN(Named Data Networking)体系结构,提出一种多层卫星网络分布式路由方法——SNDN(Satellite Named Data Networking).根据链路切换的周期性和可预知性,以时变图为建模工具,设计一个能自适应稠密和稀疏场景的路由算法来动态地计算时间相关的最快路径并附加为源路由信息,充分利用命名数据网络数据驱动的通信模式、数据包级的安全特性和逐跳转发的特点,由节点在包转发的过程中动态地完成转发表(FIB,Forwarding Information Base)和请求状态表(PIT,Pending Interest Table)的构建.可为面向未来空、天、地一体化协同组网的多层卫星网络路由研究提供一种新的思路.通过仿真实验及对比分析,验证了SNDN在路由效率和多播性能方面的优势.展开更多
基金supported by the National Science Foundation(Nos.91338115,61231008)National S&T Major Project(No.2015ZX03002006)+2 种基金the Fundamental Research Funds for the Central Universities(Nos.WRYB142208,JB140117)Shanghai Aerospace Science and Technology Innovation Fund(No.201454)the 111 Project(No.B08038).
文摘Deep space networks,satellite networks,ad hoc networks,and the Internet can be modeled as DTNs(Delay Tolerant Networks).As a fundamental problem,the maximum flow problem is of vital importance for routing and service scheduling in networks.However,there exists no permanent end-to-end path since the topology and the characteristics of links are time-variant,resulting in a crucial maximum flow problem in DTNs.In this paper,we focus on the single-source-single-sink maximum flow problem of buffer-limited DTNs,followed by a valid algorithm to solve it.First,the BTAG(Buffer-limited Time Aggregated Graph)is constructed for modeling the buffer-limited DTN.Then,on the basis of BTAG,the two-way cache transfer series and the relevant transfer rules are designed,and thus a BTAG-based maximum flow algorithm is proposed to solve the maximum flow problem in buffer-limited DTNs.Finally,a numerical example is given to demonstrate the effectiveness of the proposed algorithm.
文摘多层卫星网络的拓扑结构具有明显的时变特征,难以提供持续且稳定的端到端路径,导致高效路由问题面临着巨大的挑战.将卫星网络设计为封闭的体系结构,采用强管理或调度式控制策略会导致其无法自由、高效地实现与其它系统的协同组网.基于IP的网络体系结构在应用于多层卫星网络时又存在路由效率不高的问题.基于命名数据网络NDN(Named Data Networking)体系结构,提出一种多层卫星网络分布式路由方法——SNDN(Satellite Named Data Networking).根据链路切换的周期性和可预知性,以时变图为建模工具,设计一个能自适应稠密和稀疏场景的路由算法来动态地计算时间相关的最快路径并附加为源路由信息,充分利用命名数据网络数据驱动的通信模式、数据包级的安全特性和逐跳转发的特点,由节点在包转发的过程中动态地完成转发表(FIB,Forwarding Information Base)和请求状态表(PIT,Pending Interest Table)的构建.可为面向未来空、天、地一体化协同组网的多层卫星网络路由研究提供一种新的思路.通过仿真实验及对比分析,验证了SNDN在路由效率和多播性能方面的优势.
