基于机会网络中喷洒等待(spray and wait,SW)算法的优势,针对其在选择中继节点时的盲目性和随机性,提出一种改进的基于节点传输性能的自适应转发策略(TP-ASW)。考虑节点的剩余能量和邻居变化率,选择剩余能量大、邻居更新快的节点作为中...基于机会网络中喷洒等待(spray and wait,SW)算法的优势,针对其在选择中继节点时的盲目性和随机性,提出一种改进的基于节点传输性能的自适应转发策略(TP-ASW)。考虑节点的剩余能量和邻居变化率,选择剩余能量大、邻居更新快的节点作为中继节点;根据节点对的邻居相似度调节阈值的大小,控制不同节点传输性能和不同网络环境下的转发条件,实现自适应转发决策。仿真结果表明,相比于喷洒等待,提出的TP-ASW转发策略在取得较高传输成功率的同时,大幅降低了开销率。展开更多
针对水下传感器网络中节点能耗不均衡和能量有限的问题,提出一种能耗均衡与节能的自适应水下路由协议ECBES(energy consumption balanced and energy saving adaptive underwater routing protocol)。构建双区非均匀分层拓扑。基于能耗...针对水下传感器网络中节点能耗不均衡和能量有限的问题,提出一种能耗均衡与节能的自适应水下路由协议ECBES(energy consumption balanced and energy saving adaptive underwater routing protocol)。构建双区非均匀分层拓扑。基于能耗均衡因子,利用拓扑和节点剩余能量计算节点转发优先级,实现自适应转发节点选择,均衡网络能耗。与此同时,通过候选转发区域各分区域中节点参与转发数据包的比例确定次优候选转发区域,将次优候选转发区域作为初始策略,利用策略迭代思想确定最优候选转发区域,保证投递率的同时减少不同网络规模中重复数据包的转发,降低网络的整体能耗。仿真结果表明,ECBES相比VBF、ES-VBF和ALRP,在不同节点数量下,节点死亡率均最低,在保证数据包投递率的同时,能耗最少。展开更多
在分析现有机会网络转发控制策略的基础上,针对采用固定效用值阈值的机会网络转发控制,提出了一种基于节点能力状况的自适应转发控制策略(adaptive forwarding algorithm based on nodal capacity condition,AFNC)。该策略根据节点的能...在分析现有机会网络转发控制策略的基础上,针对采用固定效用值阈值的机会网络转发控制,提出了一种基于节点能力状况的自适应转发控制策略(adaptive forwarding algorithm based on nodal capacity condition,AFNC)。该策略根据节点的能力状况计算阈值控制因子,自适应调整不同网络传输状况以及通信机会下的数据转发条件。仿真实验表明,与现有的几种典型转发控制相比,AFNC在保证较低传输延迟和较高传输成功率的基础上,通过减少节点间的转发次数,有效地降低了网络传输开销。展开更多
This paper describes how to use an Adaptive Forward Error Correction (AFEC) algorithm to efficiently protect the critical data areas of compressed headers and UDP-Lite packets for data transport in a radio link layer ...This paper describes how to use an Adaptive Forward Error Correction (AFEC) algorithm to efficiently protect the critical data areas of compressed headers and UDP-Lite packets for data transport in a radio link layer of a wireless connection. Augmented with RoHC and UDP-Lite, for H.264 video transmissions over wireless channels in a heterogeneous wired-wireless environment, the erroneous packet payloads can be useful and better able to cope with lost packets (native UDP case), by adopting some of the erasure and error resilient modes in H.264. The context transfer during inter/intra handover is also discussed. Simu- lations demonstrated that the proposed scenario significantly improves the PSNR performance and video quality.展开更多
文摘基于机会网络中喷洒等待(spray and wait,SW)算法的优势,针对其在选择中继节点时的盲目性和随机性,提出一种改进的基于节点传输性能的自适应转发策略(TP-ASW)。考虑节点的剩余能量和邻居变化率,选择剩余能量大、邻居更新快的节点作为中继节点;根据节点对的邻居相似度调节阈值的大小,控制不同节点传输性能和不同网络环境下的转发条件,实现自适应转发决策。仿真结果表明,相比于喷洒等待,提出的TP-ASW转发策略在取得较高传输成功率的同时,大幅降低了开销率。
文摘针对水下传感器网络中节点能耗不均衡和能量有限的问题,提出一种能耗均衡与节能的自适应水下路由协议ECBES(energy consumption balanced and energy saving adaptive underwater routing protocol)。构建双区非均匀分层拓扑。基于能耗均衡因子,利用拓扑和节点剩余能量计算节点转发优先级,实现自适应转发节点选择,均衡网络能耗。与此同时,通过候选转发区域各分区域中节点参与转发数据包的比例确定次优候选转发区域,将次优候选转发区域作为初始策略,利用策略迭代思想确定最优候选转发区域,保证投递率的同时减少不同网络规模中重复数据包的转发,降低网络的整体能耗。仿真结果表明,ECBES相比VBF、ES-VBF和ALRP,在不同节点数量下,节点死亡率均最低,在保证数据包投递率的同时,能耗最少。
文摘在分析现有机会网络转发控制策略的基础上,针对采用固定效用值阈值的机会网络转发控制,提出了一种基于节点能力状况的自适应转发控制策略(adaptive forwarding algorithm based on nodal capacity condition,AFNC)。该策略根据节点的能力状况计算阈值控制因子,自适应调整不同网络传输状况以及通信机会下的数据转发条件。仿真实验表明,与现有的几种典型转发控制相比,AFNC在保证较低传输延迟和较高传输成功率的基础上,通过减少节点间的转发次数,有效地降低了网络传输开销。
基金Project (Nos. FP6-IST-2003-506997 and FP6-IST-2005-026943)supported partially by the European Information Society TechnologiesFramework Programme 6 Integrated Project: "Daidalos" (European ISTProject: Daidalos, 2003~2008)
文摘This paper describes how to use an Adaptive Forward Error Correction (AFEC) algorithm to efficiently protect the critical data areas of compressed headers and UDP-Lite packets for data transport in a radio link layer of a wireless connection. Augmented with RoHC and UDP-Lite, for H.264 video transmissions over wireless channels in a heterogeneous wired-wireless environment, the erroneous packet payloads can be useful and better able to cope with lost packets (native UDP case), by adopting some of the erasure and error resilient modes in H.264. The context transfer during inter/intra handover is also discussed. Simu- lations demonstrated that the proposed scenario significantly improves the PSNR performance and video quality.
