A novel distributed cognitive radio multichannel medium access protocol without common control channel was proposed.The protocol divided a transmission interval into two parts for exchanging control information and da...A novel distributed cognitive radio multichannel medium access protocol without common control channel was proposed.The protocol divided a transmission interval into two parts for exchanging control information and data,respectively.In addition to evaluating system saturation throughput of the proposed protocol,a three-dimensional multi channel Markov chain model to describe the sate of the cognitive users (CUs) in dynamic spectrum access was presented.The proposed analysis was applied to the packet transmission schemes employed by the basic,RTS/CTS access mechanism adopted in the normal IEEE 802.11.Analyzing the advantage of the two methods,a hybrid access mechanism was proposed to improve the system throughput.The simulation results show that the experiment results are close to the value computed by the model (less than 5%),and the proposed protocol significantly improves the performance of the system throughput by borrowing the licensed spectrum.By analyzing the dependence of throughput on system parameters,hybrid mechanism dynamically selecting access mechanism can maintain high throughput.展开更多
在分析当前Ad Hoc网络多信道MAC协议的基础上,提出了一个衡量信道质量的度量参数CQ(Channel Quality)作为信道选择的依据。并提出了一个基于接收方信道质量的多信道MAC协议MMCQ(Multi-channel MAC protocol with Channel Quali-ty of re...在分析当前Ad Hoc网络多信道MAC协议的基础上,提出了一个衡量信道质量的度量参数CQ(Channel Quality)作为信道选择的依据。并提出了一个基于接收方信道质量的多信道MAC协议MMCQ(Multi-channel MAC protocol with Channel Quali-ty of receiver),以解决多信道MAC协议常见的控制信道瓶颈和信道分配公平性问题。仿真表明:该协议在降低控制信道开销的前提下,能显著增加网络的平均吞吐量,并降低端到端平均时延。展开更多
传感器节点沿树状多跳路径逐级向Sink转发数据是无线传感器网络的主要业务模式之一。针对此类业务,该文的EBRI-MAC(Energy-efficient MAC protocol Based on Routing Information)协议提出一种对应树状路由转发关系,由父节点与子节点构...传感器节点沿树状多跳路径逐级向Sink转发数据是无线传感器网络的主要业务模式之一。针对此类业务,该文的EBRI-MAC(Energy-efficient MAC protocol Based on Routing Information)协议提出一种对应树状路由转发关系,由父节点与子节点构成虚拟群的思想;并设计了连锁邀请与CSMA/CA结合的信道接入机制以及基于虚拟群同步的周期休眠机制,以达到节能的目的。结合节点能耗因素,定义了能量有效性的性能参数,并对EBRI-MAC的能量有效性进行理论分析。通过ns-2仿真结果表明网络业务时间相关性较强时,EBRI-MAC的能量有效性优于IEEE802.11DCF和S-MAC。展开更多
基金Project(61071104) supported by the National Natural Science Foundation of China
文摘A novel distributed cognitive radio multichannel medium access protocol without common control channel was proposed.The protocol divided a transmission interval into two parts for exchanging control information and data,respectively.In addition to evaluating system saturation throughput of the proposed protocol,a three-dimensional multi channel Markov chain model to describe the sate of the cognitive users (CUs) in dynamic spectrum access was presented.The proposed analysis was applied to the packet transmission schemes employed by the basic,RTS/CTS access mechanism adopted in the normal IEEE 802.11.Analyzing the advantage of the two methods,a hybrid access mechanism was proposed to improve the system throughput.The simulation results show that the experiment results are close to the value computed by the model (less than 5%),and the proposed protocol significantly improves the performance of the system throughput by borrowing the licensed spectrum.By analyzing the dependence of throughput on system parameters,hybrid mechanism dynamically selecting access mechanism can maintain high throughput.
基金Supported by the National High-Tech Research and Development Plan of China under Grant No.2005AA121570(国家高技术研究发展计划(863))the National Basic Research Program of China under Grant No.2003CB314802(国家重点基础研究发展计划(973))
文摘在分析当前Ad Hoc网络多信道MAC协议的基础上,提出了一个衡量信道质量的度量参数CQ(Channel Quality)作为信道选择的依据。并提出了一个基于接收方信道质量的多信道MAC协议MMCQ(Multi-channel MAC protocol with Channel Quali-ty of receiver),以解决多信道MAC协议常见的控制信道瓶颈和信道分配公平性问题。仿真表明:该协议在降低控制信道开销的前提下,能显著增加网络的平均吞吐量,并降低端到端平均时延。
文摘传感器节点沿树状多跳路径逐级向Sink转发数据是无线传感器网络的主要业务模式之一。针对此类业务,该文的EBRI-MAC(Energy-efficient MAC protocol Based on Routing Information)协议提出一种对应树状路由转发关系,由父节点与子节点构成虚拟群的思想;并设计了连锁邀请与CSMA/CA结合的信道接入机制以及基于虚拟群同步的周期休眠机制,以达到节能的目的。结合节点能耗因素,定义了能量有效性的性能参数,并对EBRI-MAC的能量有效性进行理论分析。通过ns-2仿真结果表明网络业务时间相关性较强时,EBRI-MAC的能量有效性优于IEEE802.11DCF和S-MAC。
