The scheduling algorithm based on the three-way handshaking scheme in IEEE 802.16d-2004 standard has some serious problems because of the complexity of the algorithm and low scheduling efficiency. To enhance the sched...The scheduling algorithm based on the three-way handshaking scheme in IEEE 802.16d-2004 standard has some serious problems because of the complexity of the algorithm and low scheduling efficiency. To enhance the scheduling efficiency and improve the performance of multi-hop wireless mesh networks （WMNs）, one distributed scheduling algorithm that can maximize the spatial and time reuse with an interference-based network model is proposed. Compared to the graph-based network model, the proposed network model can achieve a better throughput performance with maximal spatial reuse. Furthermore, this proposed scheduling algorithm also keeps fairly scheduling to all links, with a priority-based polling policy. Both the theoretical analysis and simulation results show that this proposed distributed scheduling algorithm is simple and efficient.展开更多
The common characteristics of peer-to-peer （P2P） overlay networks and wireless multi-hop network, such as self-organization, decentralization, hop-by-hop message transmission mode and high degree of dynamicity, lead...The common characteristics of peer-to-peer （P2P） overlay networks and wireless multi-hop network, such as self-organization, decentralization, hop-by-hop message transmission mode and high degree of dynamicity, lead to research of operating wired P2P applications on wireless multi-hop networks. Wireless mesh network （WMN） as a relative static multi-hop wireless network which is extended from Ad-Hoc networks, has become one of the key technologies for providing increased network coverage of Internet infrastructures. This paper investigates the problem of enabling P2P file sharing in WMNs. A special chord algorithm--spiralchord is proposed to address the major problem in wireless file sharing system how to efficiently find resources currently available. Spiralchord put forward an identifier （ID） assignment technique based on spiral space-filling curve to integrate location-awareness with cross-layering. Location awareness aims at alleviating the mismatch of physical network topology and overlay network topology, and requires close-by IDs in logical ring of neighboring peers, while cross-layering aims at speeding up resource lookup operations, requires faraway IDs of neighboring peers. Spiralchord uses spiral curve to assign peers＇ IDs which meet the contradictory requirements of location-awareness and cross-layering. The simulation results show spiralchord is effective in reducing message overhead, and increasing lookup performance with respect to basic chord.展开更多
The pretty promising Wireless Mesh Networking technique, which is regarded as the next generation wireless Internet, not only possesses the normal features of wireless networks, but also has the advantages of multi-ho...The pretty promising Wireless Mesh Networking technique, which is regarded as the next generation wireless Internet, not only possesses the normal features of wireless networks, but also has the advantages of multi-hop, self-organizing, etc. However, the great strength of the Mesh Networks also lead to a serious problem in the perspective of network security. This paper starts with the security issue of WMN routing and puts forward the corresponding solutions to the two kinds of routings' security, such as adding the public/private (Pi/Si) key to the AODV to solve the problem of black hole and adding the credit value of nodes to the DSR to improve the security.展开更多
基金This work is supported by the National Natural Science Foundation of China （60572120, 60602058）；the Hi-Tech Research and Development Program of China （2006AA01Z257）.
文摘The scheduling algorithm based on the three-way handshaking scheme in IEEE 802.16d-2004 standard has some serious problems because of the complexity of the algorithm and low scheduling efficiency. To enhance the scheduling efficiency and improve the performance of multi-hop wireless mesh networks （WMNs）, one distributed scheduling algorithm that can maximize the spatial and time reuse with an interference-based network model is proposed. Compared to the graph-based network model, the proposed network model can achieve a better throughput performance with maximal spatial reuse. Furthermore, this proposed scheduling algorithm also keeps fairly scheduling to all links, with a priority-based polling policy. Both the theoretical analysis and simulation results show that this proposed distributed scheduling algorithm is simple and efficient.
基金supported by the Longitudinal Scientific Research of Wuhan University of Technology of China (201109YB01)
文摘The common characteristics of peer-to-peer （P2P） overlay networks and wireless multi-hop network, such as self-organization, decentralization, hop-by-hop message transmission mode and high degree of dynamicity, lead to research of operating wired P2P applications on wireless multi-hop networks. Wireless mesh network （WMN） as a relative static multi-hop wireless network which is extended from Ad-Hoc networks, has become one of the key technologies for providing increased network coverage of Internet infrastructures. This paper investigates the problem of enabling P2P file sharing in WMNs. A special chord algorithm--spiralchord is proposed to address the major problem in wireless file sharing system how to efficiently find resources currently available. Spiralchord put forward an identifier （ID） assignment technique based on spiral space-filling curve to integrate location-awareness with cross-layering. Location awareness aims at alleviating the mismatch of physical network topology and overlay network topology, and requires close-by IDs in logical ring of neighboring peers, while cross-layering aims at speeding up resource lookup operations, requires faraway IDs of neighboring peers. Spiralchord uses spiral curve to assign peers＇ IDs which meet the contradictory requirements of location-awareness and cross-layering. The simulation results show spiralchord is effective in reducing message overhead, and increasing lookup performance with respect to basic chord.
文摘The pretty promising Wireless Mesh Networking technique, which is regarded as the next generation wireless Internet, not only possesses the normal features of wireless networks, but also has the advantages of multi-hop, self-organizing, etc. However, the great strength of the Mesh Networks also lead to a serious problem in the perspective of network security. This paper starts with the security issue of WMN routing and puts forward the corresponding solutions to the two kinds of routings' security, such as adding the public/private (Pi/Si) key to the AODV to solve the problem of black hole and adding the credit value of nodes to the DSR to improve the security.
基金上海市教委自然科学基金( the Natural Science Foundation of Shanghai Municipal Education Commission of China under Grant No. 05JC05051) 上海市教委E研究院-上海高校网格项目( "SEC E- Institute: Shanghai High Institutions Grid"Project under Grant No. 200312)。
文摘路由器节点承载WMNs(Wireless Mesh Networks)的主要业务,决定网络的整体性能,其业务性能建模与分析是当前研究的热点内容。本文基于802.11 OFDM物理层计算的分组平均服务时间,采用排队论分析WMN路由器节点业务性能的理论模型,给出节点业务性能的计算方法,通过理论分析与仿真验证模型的准确性,并给出使用归一化的模型参数的简化计算方法。分析表明,在相对稳定的网络环境中,路由器节点的性能与业务到达模型相关,需要采用不同的模型和方法分析VBR(Variable Bit Rate)和CBR(Constant Bit Rate)业务的性能;在动态的网络中,节点性能与业务到达过程无关,采用泊松到达可以准确地分析不同业务的性能。本文建模的基础是分组平均服务时间,使分析模型与实际的网络形态无关;基于归一化参数的算法也增大了模型的适应性,使其可以应用在网络规划设计、业务接入控制和分组调度等诸多方面。
