This paper investigates the maximum network through- put for resource-constrained space networks based on the delay and disruption-tolerant networking （DTN） architecture. Specifically, this paper proposes a methodol...This paper investigates the maximum network through- put for resource-constrained space networks based on the delay and disruption-tolerant networking （DTN） architecture. Specifically, this paper proposes a methodology for calculating the maximum network throughput of multiple transmission tasks under storage and delay constraints over a space network. A mixed-integer linear programming （MILP） is formulated to solve this problem. Simula- tions results show that the proposed methodology can successfully calculate the optimal throughput of a space network under storage and delay constraints, as well as a clear, monotonic relationship between end-to-end delay and the maximum network throughput under storage constraints. At the same time, the optimization re- sults shine light on the routing and transport protocol design in space communication, which can be used to obtain the optimal network throughput.展开更多
跨数据中心网络是处于不同地区的数据中心网络(Data Center Networks,DCNs)通过广域网(Wide-Area Network,WAN)连接组成的网络,分布式应用通常基于该网络为用户提供高质量的服务。DCNs和WAN的缓冲区大小、往返时延存在显著差异,这导致...跨数据中心网络是处于不同地区的数据中心网络(Data Center Networks,DCNs)通过广域网(Wide-Area Network,WAN)连接组成的网络,分布式应用通常基于该网络为用户提供高质量的服务。DCNs和WAN的缓冲区大小、往返时延存在显著差异,这导致现有的Cubic拥塞控制算法在跨数据中心网络场景下出现降速不准确、丢包率过高以及与其他拥塞控制算法兼容性差等问题。针对以上挑战,提出了一种通过匹配不同发送速率模式的改进Cubic算法Cubic+。具体地,Cubic+整合了网络中的时延、ECN(Explicit Congestion Notification)和丢包信号。当拥塞发生在浅缓冲交换机时,Cubic+会周期性地排空队列;当拥塞发生在深缓冲路由器时,Cubic+会快速减少堆积的数据包。基于大规模NS3仿真实验结果表明,在跨数据中心网络流量模型下,Cubic+与现有流行算法相比,平均流完成时间最多减少了20.77%,第99百分位流完成时间最多减少了15.88%,为跨数据中心网络提供了一种高吞吐的拥塞控制算法。展开更多
海上异构无线网络覆盖下的业务需求和节点多种多样,这就要求网络资源在分配时需要兼顾匹配性和网络性能。相邻多节点在选择无线网络时,易产生策略冲突并大量接入同一网络,进而导致网络负载不均衡、接入阻塞率高和服务质量(quality of se...海上异构无线网络覆盖下的业务需求和节点多种多样,这就要求网络资源在分配时需要兼顾匹配性和网络性能。相邻多节点在选择无线网络时,易产生策略冲突并大量接入同一网络,进而导致网络负载不均衡、接入阻塞率高和服务质量(quality of service,Qos)降低。针对以上问题提出一种基于网络评价和时隙分配的网络接入选择算法,设计网络评价模块、时隙分配模块和接入决策模块,通过业务评价和阻塞率估计对可选网络进行综合评价以提高匹配性,根据节点执行业务的优先级对多节点进行时隙分配,依序优化网络接入策略。仿真结果表明,相对于负载均衡和多属性决策算法,所提算法的节点平均接入阻塞率降低了32.09%,20.87%,节点平均吞吐量提升了76.90%,33.25%,网络的负载均衡性和传输效率均得到有效提升。展开更多
基金supported by the National Natural Sciences Foundation of China(6113200261321061+3 种基金6123101161201183)the National Basic Research Program of China(2014CB340206)the Tsinghua University Initiative Scientific Research Program(2011Z05117)
文摘This paper investigates the maximum network through- put for resource-constrained space networks based on the delay and disruption-tolerant networking （DTN） architecture. Specifically, this paper proposes a methodology for calculating the maximum network throughput of multiple transmission tasks under storage and delay constraints over a space network. A mixed-integer linear programming （MILP） is formulated to solve this problem. Simula- tions results show that the proposed methodology can successfully calculate the optimal throughput of a space network under storage and delay constraints, as well as a clear, monotonic relationship between end-to-end delay and the maximum network throughput under storage constraints. At the same time, the optimization re- sults shine light on the routing and transport protocol design in space communication, which can be used to obtain the optimal network throughput.
文摘海上异构无线网络覆盖下的业务需求和节点多种多样,这就要求网络资源在分配时需要兼顾匹配性和网络性能。相邻多节点在选择无线网络时,易产生策略冲突并大量接入同一网络,进而导致网络负载不均衡、接入阻塞率高和服务质量(quality of service,Qos)降低。针对以上问题提出一种基于网络评价和时隙分配的网络接入选择算法,设计网络评价模块、时隙分配模块和接入决策模块,通过业务评价和阻塞率估计对可选网络进行综合评价以提高匹配性,根据节点执行业务的优先级对多节点进行时隙分配,依序优化网络接入策略。仿真结果表明,相对于负载均衡和多属性决策算法,所提算法的节点平均接入阻塞率降低了32.09%,20.87%,节点平均吞吐量提升了76.90%,33.25%,网络的负载均衡性和传输效率均得到有效提升。
