To adjust the variance of source rate in linear broadcast networks,global encoding kernels should have corresponding dimensions to instruct the decoding process.The algorithm of constructing such global encoding kerne...To adjust the variance of source rate in linear broadcast networks,global encoding kernels should have corresponding dimensions to instruct the decoding process.The algorithm of constructing such global encoding kernels is to adjust heterogeneous network to possible link failures.Linear algebra,graph theory and group theory are applied to construct one series of global encoding kernels which are applicable to all source rates.The effectiveness and existence of such global encoding kernels are proved.Based on information flow,the algorithm of construction is explicitly given within polynomial time(|E·|T|ω2max) and the memory complexity of algorithm is O(|E|).Both time and memory complexity of this algorithm proposed can be O(ωmax) less than those of algorithms in related works.展开更多
现有关于无线定向网络广播的研究主要集中于如何选择中继节点或计算转发概率以提升分组递交率,减少广播冗余,但未对中继节点选择及波束指向计算开展联合设计,导致源节点及中继节点在广播过程中存在冗余指向,增加了消息转发次数。为提升...现有关于无线定向网络广播的研究主要集中于如何选择中继节点或计算转发概率以提升分组递交率,减少广播冗余,但未对中继节点选择及波束指向计算开展联合设计,导致源节点及中继节点在广播过程中存在冗余指向,增加了消息转发次数。为提升无线定向网络广播效率,提出一种基于最大完全子图与最小树形图的无线定向网络广播算法(maximum complete subgraph and minimum arborescence based directional broadcasting algorithm,MCSMA)。算法首先利用最大完全子图理论计算源节点或中继节点波束指向,使单个波束指向覆盖的邻居节点数量最多,然后利用最小树形图理论选择中继节点,使中继节点使用少量波束覆盖全网所有节点,降低广播过程中的消息转发次数。仿真表明,所提算法可有效减少广播过程中源节点和中继节点的波束指向次数,提升定向广播效率。展开更多
Broadcasting is an important operation and been widely used in wireless sensor networks （WSNs）. These networks are power constrained as nodes operate with limited battery power. Wireless sensor networks are spatial ...Broadcasting is an important operation and been widely used in wireless sensor networks （WSNs）. These networks are power constrained as nodes operate with limited battery power. Wireless sensor networks are spatial graphs that have much more clustered and much high path-length characteristics. After considering energy- efficient broadcasting in such networks, by combining the small-world characteristic of WSNs and the properties of ant algorithm to quickly identify an optimal path, small-world power-aware broadcast algorithm is introduced and evaluated. Given different densities of network, simulation results show that our algorithm significantly improves life of networks and also reduces communication distances and power consumption.展开更多
Problems of the current IGMP mechanism were identified, such as unnecessary periodic probing of hosts and leave latency, which wastes bandwidth and cause more traffic and overhead. Alternative mechanism that preserve ...Problems of the current IGMP mechanism were identified, such as unnecessary periodic probing of hosts and leave latency, which wastes bandwidth and cause more traffic and overhead. Alternative mechanism that preserve the IP multicast model but employ join/leave messages to track local group membership for broadcast LANs (shared medium LANs) was proposed in this paper. We describe the implementation requirements of the new mechanism and compare it to existing one, demonstrating that join/leave approach is uniformly superior for the environment of broadcast LANs.展开更多
在1090ES广播式自动相关监视(ADS-B)模式下,针对飞机的位置信息中涉及经纬度编解码算法的内容进行了简要介绍,主要涉及经纬度编码、本地解码、全球解码算法的具体实现步骤。通过检飞验证,研究结果表明,简洁位置报告(Compact Position Re...在1090ES广播式自动相关监视(ADS-B)模式下,针对飞机的位置信息中涉及经纬度编解码算法的内容进行了简要介绍,主要涉及经纬度编码、本地解码、全球解码算法的具体实现步骤。通过检飞验证,研究结果表明,简洁位置报告(Compact Position Reporting,CPR)编解码具有很高的有效性和准确性,能有效提高成功接收报文的概率。展开更多
基金Project(60872005) supported by National Natural Science Foundation of China
文摘To adjust the variance of source rate in linear broadcast networks,global encoding kernels should have corresponding dimensions to instruct the decoding process.The algorithm of constructing such global encoding kernels is to adjust heterogeneous network to possible link failures.Linear algebra,graph theory and group theory are applied to construct one series of global encoding kernels which are applicable to all source rates.The effectiveness and existence of such global encoding kernels are proved.Based on information flow,the algorithm of construction is explicitly given within polynomial time(|E·|T|ω2max) and the memory complexity of algorithm is O(|E|).Both time and memory complexity of this algorithm proposed can be O(ωmax) less than those of algorithms in related works.
文摘现有关于无线定向网络广播的研究主要集中于如何选择中继节点或计算转发概率以提升分组递交率,减少广播冗余,但未对中继节点选择及波束指向计算开展联合设计,导致源节点及中继节点在广播过程中存在冗余指向,增加了消息转发次数。为提升无线定向网络广播效率,提出一种基于最大完全子图与最小树形图的无线定向网络广播算法(maximum complete subgraph and minimum arborescence based directional broadcasting algorithm,MCSMA)。算法首先利用最大完全子图理论计算源节点或中继节点波束指向,使单个波束指向覆盖的邻居节点数量最多,然后利用最小树形图理论选择中继节点,使中继节点使用少量波束覆盖全网所有节点,降低广播过程中的消息转发次数。仿真表明,所提算法可有效减少广播过程中源节点和中继节点的波束指向次数,提升定向广播效率。
文摘Broadcasting is an important operation and been widely used in wireless sensor networks （WSNs）. These networks are power constrained as nodes operate with limited battery power. Wireless sensor networks are spatial graphs that have much more clustered and much high path-length characteristics. After considering energy- efficient broadcasting in such networks, by combining the small-world characteristic of WSNs and the properties of ant algorithm to quickly identify an optimal path, small-world power-aware broadcast algorithm is introduced and evaluated. Given different densities of network, simulation results show that our algorithm significantly improves life of networks and also reduces communication distances and power consumption.
文摘Problems of the current IGMP mechanism were identified, such as unnecessary periodic probing of hosts and leave latency, which wastes bandwidth and cause more traffic and overhead. Alternative mechanism that preserve the IP multicast model but employ join/leave messages to track local group membership for broadcast LANs (shared medium LANs) was proposed in this paper. We describe the implementation requirements of the new mechanism and compare it to existing one, demonstrating that join/leave approach is uniformly superior for the environment of broadcast LANs.
文摘在1090ES广播式自动相关监视(ADS-B)模式下,针对飞机的位置信息中涉及经纬度编解码算法的内容进行了简要介绍,主要涉及经纬度编码、本地解码、全球解码算法的具体实现步骤。通过检飞验证,研究结果表明,简洁位置报告(Compact Position Reporting,CPR)编解码具有很高的有效性和准确性,能有效提高成功接收报文的概率。
