In mobile ad hoc networks （MANETs）, if a mnltihop route breaks, route maintenance is typically performed to establish a new route which causes high control overhead and long packet delay. To decrease the time of rec...In mobile ad hoc networks （MANETs）, if a mnltihop route breaks, route maintenance is typically performed to establish a new route which causes high control overhead and long packet delay. To decrease the time of recovery and the overhead of maintenance, a new route maintenance mechanism in which the maintenance is confined to the vicinity of the broken link is proposed. This mechanism patches broken route through some other nodes in which only nodes near the broken link（s） may need to be substituted and the rest of nodes can be retained on the route. The broken link can be repaired without considering its relative position in the whole path, so the abihty of dealing with hnk failure is improved obviously. Simulation results show that the proposed strategy improves network performance significantly, such as in merits of control overhead and packet delay.展开更多
A novel reliable routing algorithm in mobile ad hoc networks using fuzzy Petri net with its reasoning mechanism was proposed to increase the reliability during the routing selection. The algorithm allows the structure...A novel reliable routing algorithm in mobile ad hoc networks using fuzzy Petri net with its reasoning mechanism was proposed to increase the reliability during the routing selection. The algorithm allows the structured representation of network topology, which has a fuzzy reasoning mechanism for finding the routing sprouting tree from the source node to the destination node in the mobile ad boc environment. Finally, by comparing the degree of reliability in the routing sprouting tree, the most reliable route can be computed. The algorithm not only offers the local reliability between each neighboring node, but also provides global reliability for the whole selected route. The algorithm can be applied to most existing on-demand routing protocols, and the simulation results show that the routing reliability is increased by more than 80% when applying the proposed algorithm to the ad hoc on demand distance vector routing protocol.展开更多
为了保证飞行自组网(flying ad hoc network,FANET)在拓扑快速变化下的稳定信息传输,在期望传输次数(expected transmission count,ETX)度量的无线自组网按需平面距离向量(ad hoc on-demand distant vector,AODV)路由协议基础上,提出了...为了保证飞行自组网(flying ad hoc network,FANET)在拓扑快速变化下的稳定信息传输,在期望传输次数(expected transmission count,ETX)度量的无线自组网按需平面距离向量(ad hoc on-demand distant vector,AODV)路由协议基础上,提出了一种基于K-means聚类算法的K-AODV-ETX路由协议。协议采用到目的节点的跳数、错误传输次数、节点缓冲空间3个聚类特征对无人机节点进行分类,RREQ分组转发时选择最佳集群进行路由发现,最后采用ETX机制选择ETX值和最小路径进行数据传输。结果表明,K-AODV-ETX路由协议与现有的AODV-ETX路由协议和ND-AODV-ETX路由协议相比,能够有效保持网络的吞吐量,在端到端数据包投递率性能上稍有下降,在路由开销和时延性能方面有着显著的效果。K-AODV-ETX路由协议优化了路由发现过程的泛洪广播机制,有效改善了现有的ETX机制下协议的高开销、高延迟问题,并保证了网络的吞吐量,为设计低时延路由协议以及平衡ETX机制带来的高开销问题提供了一种有效的方法。展开更多
In Shadow-Fading model, it is difficult to achieve higher Packet Delivery Ratio (PDR) due to the effects of large scale fading. The main goal of this paper is to improve the PDR in Shadow-Fading environment. To achiev...In Shadow-Fading model, it is difficult to achieve higher Packet Delivery Ratio (PDR) due to the effects of large scale fading. The main goal of this paper is to improve the PDR in Shadow-Fading environment. To achieve this objective a protocol has been proposed that discovers backup routes for active sessions. These backup routes salvage the packets of active session in case of active route failure. It is found by research that proactively maintaining backup routes for ac-tive sessions can noticeably improve the PDR in Shadow-Fading environment. This protocol has been implemented with a mechanism of having backup routes and simulations have been conducted by using both node disjoint paths and link disjoint paths. Comparisons have been made between new protocol as well as AODV protocol. Simulation has been carried out using Network Simulator 2 (NS2) and the results show that the proposed QoSAR protocol exhibits higher PDR than AODV protocol in Shadow-fading environment.展开更多
针对群组机器人系统在应急场景下移动频繁、能量有限的特点,提出了一种基于能量与速度的分簇自组织按需距离矢量协议(Clustered Ad hoc On-Demand Distance Vector Protocol Based on Energy and Speed,ESC-AODV),以延长群组机器人网络...针对群组机器人系统在应急场景下移动频繁、能量有限的特点,提出了一种基于能量与速度的分簇自组织按需距离矢量协议(Clustered Ad hoc On-Demand Distance Vector Protocol Based on Energy and Speed,ESC-AODV),以延长群组机器人网络运行时间,提高通信可靠性。用路由性能代替跳数作为路由判据,目的节点在重复接收到路由请求(Route Request,RREQ)数据包时,若路由性能更小,则回复路由应答(Routing Reply,RREP)数据包,以此选择更好的路由,引入分簇结构,通过簇头和网关组成的骨干网络减少广播洪泛次数。实验结果证明,节点数量多时,改进的ESC-AODV协议在延长网络生存时间的同时,平均端到端时延、数据包投递率、吞吐量和路由开销均优于AODV以及基于能量、负载和速度的AODV路由协议(AODV Routing Protocol Based on Energy,Load and Speed,ELS-AODV)。ESC-AODV协议能够节约网络能量,提高可靠性,获得更优的网络性能。展开更多
为了降低无线网格网(Wireless mesh network,WMN)中节点间的端到端传输时延,该文提出了一种改进的基于负载均衡与时延约束的自组织网络按需距离矢量路由协议(Enhancedrouting protocol on ad hoc on-demand distance vector(AODV)with l...为了降低无线网格网(Wireless mesh network,WMN)中节点间的端到端传输时延,该文提出了一种改进的基于负载均衡与时延约束的自组织网络按需距离矢量路由协议(Enhancedrouting protocol on ad hoc on-demand distance vector(AODV)with load balance and delay restriction,BD_AODV)。BD_AODV要求源节点在进行路由请求时,包含对传输时延的要求和节点的负载信息,选择满足传输时延要求的节点转发路由请求至目的节点,目的节点搜集并将每条链路的平均负载反馈给源节点,使其能够据此选择合适的传输路由。网络模拟软件仿真实验表明,BD_AODV有助于保持网络的负载均衡,缩短端到端的传输时延,减少数据包丢失,提高无线网格网的服务质量。展开更多
基金the National High Technology Research and Development Progamme of China(No2005AA123820)the National Natural Science Foundation of China(No60472052 and No10577007)
文摘In mobile ad hoc networks （MANETs）, if a mnltihop route breaks, route maintenance is typically performed to establish a new route which causes high control overhead and long packet delay. To decrease the time of recovery and the overhead of maintenance, a new route maintenance mechanism in which the maintenance is confined to the vicinity of the broken link is proposed. This mechanism patches broken route through some other nodes in which only nodes near the broken link（s） may need to be substituted and the rest of nodes can be retained on the route. The broken link can be repaired without considering its relative position in the whole path, so the abihty of dealing with hnk failure is improved obviously. Simulation results show that the proposed strategy improves network performance significantly, such as in merits of control overhead and packet delay.
文摘A novel reliable routing algorithm in mobile ad hoc networks using fuzzy Petri net with its reasoning mechanism was proposed to increase the reliability during the routing selection. The algorithm allows the structured representation of network topology, which has a fuzzy reasoning mechanism for finding the routing sprouting tree from the source node to the destination node in the mobile ad boc environment. Finally, by comparing the degree of reliability in the routing sprouting tree, the most reliable route can be computed. The algorithm not only offers the local reliability between each neighboring node, but also provides global reliability for the whole selected route. The algorithm can be applied to most existing on-demand routing protocols, and the simulation results show that the routing reliability is increased by more than 80% when applying the proposed algorithm to the ad hoc on demand distance vector routing protocol.
文摘为了保证飞行自组网(flying ad hoc network,FANET)在拓扑快速变化下的稳定信息传输,在期望传输次数(expected transmission count,ETX)度量的无线自组网按需平面距离向量(ad hoc on-demand distant vector,AODV)路由协议基础上,提出了一种基于K-means聚类算法的K-AODV-ETX路由协议。协议采用到目的节点的跳数、错误传输次数、节点缓冲空间3个聚类特征对无人机节点进行分类,RREQ分组转发时选择最佳集群进行路由发现,最后采用ETX机制选择ETX值和最小路径进行数据传输。结果表明,K-AODV-ETX路由协议与现有的AODV-ETX路由协议和ND-AODV-ETX路由协议相比,能够有效保持网络的吞吐量,在端到端数据包投递率性能上稍有下降,在路由开销和时延性能方面有着显著的效果。K-AODV-ETX路由协议优化了路由发现过程的泛洪广播机制,有效改善了现有的ETX机制下协议的高开销、高延迟问题,并保证了网络的吞吐量,为设计低时延路由协议以及平衡ETX机制带来的高开销问题提供了一种有效的方法。
文摘In Shadow-Fading model, it is difficult to achieve higher Packet Delivery Ratio (PDR) due to the effects of large scale fading. The main goal of this paper is to improve the PDR in Shadow-Fading environment. To achieve this objective a protocol has been proposed that discovers backup routes for active sessions. These backup routes salvage the packets of active session in case of active route failure. It is found by research that proactively maintaining backup routes for ac-tive sessions can noticeably improve the PDR in Shadow-Fading environment. This protocol has been implemented with a mechanism of having backup routes and simulations have been conducted by using both node disjoint paths and link disjoint paths. Comparisons have been made between new protocol as well as AODV protocol. Simulation has been carried out using Network Simulator 2 (NS2) and the results show that the proposed QoSAR protocol exhibits higher PDR than AODV protocol in Shadow-fading environment.
文摘针对群组机器人系统在应急场景下移动频繁、能量有限的特点,提出了一种基于能量与速度的分簇自组织按需距离矢量协议(Clustered Ad hoc On-Demand Distance Vector Protocol Based on Energy and Speed,ESC-AODV),以延长群组机器人网络运行时间,提高通信可靠性。用路由性能代替跳数作为路由判据,目的节点在重复接收到路由请求(Route Request,RREQ)数据包时,若路由性能更小,则回复路由应答(Routing Reply,RREP)数据包,以此选择更好的路由,引入分簇结构,通过簇头和网关组成的骨干网络减少广播洪泛次数。实验结果证明,节点数量多时,改进的ESC-AODV协议在延长网络生存时间的同时,平均端到端时延、数据包投递率、吞吐量和路由开销均优于AODV以及基于能量、负载和速度的AODV路由协议(AODV Routing Protocol Based on Energy,Load and Speed,ELS-AODV)。ESC-AODV协议能够节约网络能量,提高可靠性,获得更优的网络性能。
文摘为了降低无线网格网(Wireless mesh network,WMN)中节点间的端到端传输时延,该文提出了一种改进的基于负载均衡与时延约束的自组织网络按需距离矢量路由协议(Enhancedrouting protocol on ad hoc on-demand distance vector(AODV)with load balance and delay restriction,BD_AODV)。BD_AODV要求源节点在进行路由请求时,包含对传输时延的要求和节点的负载信息,选择满足传输时延要求的节点转发路由请求至目的节点,目的节点搜集并将每条链路的平均负载反馈给源节点,使其能够据此选择合适的传输路由。网络模拟软件仿真实验表明,BD_AODV有助于保持网络的负载均衡,缩短端到端的传输时延,减少数据包丢失,提高无线网格网的服务质量。
