Wireless Mesh Network (WMN) is a new-type wireless network. Its core idea is that any of its wireless equipment can act as both an Access Point (AP) and a router. Each node in the network can send and receive signals ...Wireless Mesh Network (WMN) is a new-type wireless network. Its core idea is that any of its wireless equipment can act as both an Access Point (AP) and a router. Each node in the network can send and receive signals as well as directly communicate with one or several peer nodes. One important issue to be considered in wireless Mesh networks is how to secure reliable data transmission in multi-hop links. To solve the problem, the 3GPP system architecture proposes two functionalities: ARQ and HARQ. This paper presents two HARQ schemes, namely hop-by-hop and edge-to-edge, and three ARQ schemes: hop-by-hop, edge-to-edge, and last-hop. Moreover, it proposes three solutions for WMNs from the perspective of protocol stock design: layered cooperative mechanism, relay ARQ mechanism and multi-hop mechanism.展开更多
随着能源需求的不断增长和电力系统规模的扩大,配电网输电方向的变化成为影响系统可靠性的重要因素之一。通过深入分析输电方向变化的机理,揭示其基本原理、与电网稳定性的关系以及对系统频率、电压等参数的影响机理。在此基础上,分析...随着能源需求的不断增长和电力系统规模的扩大,配电网输电方向的变化成为影响系统可靠性的重要因素之一。通过深入分析输电方向变化的机理,揭示其基本原理、与电网稳定性的关系以及对系统频率、电压等参数的影响机理。在此基础上,分析系统可靠性的影响,包括可靠性评估指标与方法、输电方向变化对系统可用性的影响以及对系统平均故障间隔时间(Mean Time Between Failure,MTBF)的影响。针对发现的问题,提出一系列优化策略与措施,旨在提高配电网的可靠性和稳定性。展开更多
在延迟容忍移动传感器网络(Delay Tolerant Mobile Senor Networks,DTMSN)的数据传输过程中容易出现数据丢失及节点因能量耗尽而导致网络生存时间减少的问题.针对上述问题本文提出了基于最优距离的可靠节能传输策略,该传输策略利用距离...在延迟容忍移动传感器网络(Delay Tolerant Mobile Senor Networks,DTMSN)的数据传输过程中容易出现数据丢失及节点因能量耗尽而导致网络生存时间减少的问题.针对上述问题本文提出了基于最优距离的可靠节能传输策略,该传输策略利用距离与能量的关系解决了DTMSN中的三个重要问题:可靠性、能源效率、网络生存时间.首先,在链路质量保证下,引入了"可靠节能距离"和"可靠能量平衡距离"两个概念.此外,通过分析节点间距离、节点运动方向及节点当前剩余能量来确定节点的综合效用值,最后根据综合效用值的大小来路由消息.实验结果表明,该策略显著提高了消息的投递率及可靠性保证下传感器节点的能量利用率,延长了网络的生存时间.展开更多
文摘Wireless Mesh Network (WMN) is a new-type wireless network. Its core idea is that any of its wireless equipment can act as both an Access Point (AP) and a router. Each node in the network can send and receive signals as well as directly communicate with one or several peer nodes. One important issue to be considered in wireless Mesh networks is how to secure reliable data transmission in multi-hop links. To solve the problem, the 3GPP system architecture proposes two functionalities: ARQ and HARQ. This paper presents two HARQ schemes, namely hop-by-hop and edge-to-edge, and three ARQ schemes: hop-by-hop, edge-to-edge, and last-hop. Moreover, it proposes three solutions for WMNs from the perspective of protocol stock design: layered cooperative mechanism, relay ARQ mechanism and multi-hop mechanism.
文摘随着能源需求的不断增长和电力系统规模的扩大,配电网输电方向的变化成为影响系统可靠性的重要因素之一。通过深入分析输电方向变化的机理,揭示其基本原理、与电网稳定性的关系以及对系统频率、电压等参数的影响机理。在此基础上,分析系统可靠性的影响,包括可靠性评估指标与方法、输电方向变化对系统可用性的影响以及对系统平均故障间隔时间(Mean Time Between Failure,MTBF)的影响。针对发现的问题,提出一系列优化策略与措施,旨在提高配电网的可靠性和稳定性。
文摘在延迟容忍移动传感器网络(Delay Tolerant Mobile Senor Networks,DTMSN)的数据传输过程中容易出现数据丢失及节点因能量耗尽而导致网络生存时间减少的问题.针对上述问题本文提出了基于最优距离的可靠节能传输策略,该传输策略利用距离与能量的关系解决了DTMSN中的三个重要问题:可靠性、能源效率、网络生存时间.首先,在链路质量保证下,引入了"可靠节能距离"和"可靠能量平衡距离"两个概念.此外,通过分析节点间距离、节点运动方向及节点当前剩余能量来确定节点的综合效用值,最后根据综合效用值的大小来路由消息.实验结果表明,该策略显著提高了消息的投递率及可靠性保证下传感器节点的能量利用率,延长了网络的生存时间.
