基于社会上下文认知的机会路由算法

无线智能设备的普遍使用促进了机会网络的发展.这类网络处于间歇性连接状态,以自组织方式转发数据.路由协议设计时考虑节点携带者的社会特征和日常行为能够提高机会网络的性能.提出了一种基于社会上下文认知的机会路由算法SCOR,该算法利用网络中的社会上下文信息,通过BP神经网络模型预测节点的移动行为.路由决策过程充分考虑移动节点活动的时间和空间属性,当接收节点与发送节点同时处于网络中的同一连通域时,数据转发采用同步方式,否则采用异步方式.仿真分析和实验结果表明,与其它经典算法相比,SCOR算法提高了数据成功转发的比率,减少了网络的开销.     

分布式能量均衡的WSN动态数据转发策略

针对无线传感器网络中存在的能量空洞问题,该文提出一种能量均衡的层次型数据转发策略。根据节点可用能量、节点之间相对位置及不同网络区域簇头能量消耗速率构建非均匀层次化结构。进而,综合考虑节点簇内通信开销和节点关系选取中继转发节点,并在多跳簇间数据转发时执行数据融合进一步降低转发数据量以实现簇间多跳通信的能量有效性。数值结果表明,所提机制可以有效地均衡网络负载,延长网络生命周期,改善网络数据转发性能。     

编码节点动态管理的间断连接无线网络数据转发机制简

网络编码方法能够有效地提高间断连接无线网络的资源利用率,但编码节点的数量需要根据网络状态动态地调整。为有效提高网络资源利用率,提出一种带有编码节点动态管理的间断连接无线网络数据转发机制。节点根据当前网络状态,以分布式的方式确定最优化编码节点数量,进而,综合考虑社会属性及可用资源两方面因素,动态地选取编码节点,以较低的开销实现可靠数据转发。仿真结果表明所提出的机制充分利用了节点间的连接机会,提高了网络资源利用率。     

无线传感器网络中利用随机网络编码的低能耗可靠机会路由

无线传感器网络中节点大多采用电池供电,让节点以低能耗将采集的数据传递到信宿,对无线传感器网络有效运行极为重要.该文提出了能量有效的可靠机会路由EROR（Energy-efficient Reliable Opportunistic Routing）,它利用结合节点剩余能量和链路上收发双方的总能耗的转发代价,选择转发节点集合（简称“转发集”）、主转发节点和协助转发节点,让节点调节发射功率并利用随机线性编码把数据包分片编码发送到转发集,进而以多跳方式把数据可靠低能耗地传递到信宿.仿真结果表明：在网络生存时间和能耗方面,EROR比已有路由策略CodePower更优.     

软件定义WSN规则一致更新研究

遵循控制转发分离思想,软件定义无线传感器网络（Wireless Sensor Network,WSN）数据转发采用基于流的实现方式.因此,软件定义WSN规则更新过程中节点行为可能违背网络属性一致性.针对此,提出每包前向一致性概念,并证明其可保持所有网络属性的更新一致性.在此基础上,通过引入缓存节点与缓存规则简化规则依赖关系,提出一种规则前向一致更新算法,在满足每包前向一致性的同时,支持规则快速并行更新.实验结果表明,算法在规则开销、更新时间和通信开销等关键性能指标上具有较为明显的优势.     

节点相似度感知的社会化间断连接无线网络结构检测机制

间断连接无线网络中的节点采用"存储、携带、转发"的方式传输消息,网络中的节点具有较强的社会属性。该文提出一种基于相似度和标签传播的网络结构检测机制,节点以运动过程所经历的社区状态为依据,描述自身的中心度,进而,采用带有约束条件的标签传播方法,更新网络结构检测状态,最终完成社区结构划分。仿真结果表明,所提出的检测算法具有较高的准确性,适用于多种复杂网络结构。     

基于多目标的MIMO无线mesh网络信道优化策略

MIMO是一种可有效提高无线网络信道带宽的技术。将MIMO技术应用在无线mesh网络中会遇到信道干扰和无线节点之间无协同策略等问题,导致网络效率降低。基于无线mesh网络中节点的多属性特征,以节点属性和内容分发为约束,提出了基于多目标优化算法与多层分发联合的调度和优化策略。实验结果表明,该算法能有效降低无线mesh网络分发数据过程中的时延,提高网络的吞吐表现和服务质量。     

新型无线紫外光协作通信网络性能分析与研究

为进一步提高无线紫外光通信网络的信息传输质量和网络性能,提出了一种新型无线紫外光协作通信网络,网络中各节点采用解码转发方式,设定各节点优先级,从而实现了网络节点实时转发的协作策略。仿真分析了有无缓存设置和有无协作条件下无线紫外光通信网络的归一化吞吐量、各节点平均时延等性能。仿真结果表明：无缓存设置时,随着数据帧传输成功率的增加,高优先级节点一直有较高的归一化吞吐量,而低优先级节点数据帧丢失,归一化吞吐量下降;有缓存设置时,随着缓存的增加,各节点归一化吞吐量均有所增加;与无协作相比,有协作的紫外光通信网络具有更高的节点归一化吞吐量和平均时延。     

恶意节点容忍的间断连接无线网络消息转发策略

间断连接无线网络中的节点以协作方式完成消息投递,恶意节点将严重影响网络性能。利用节点历史行为信息,该文提出一种恶意节点容忍的消息转发策略,节点结合直接观察信息与邻居节点的推荐信息,通过动态推荐声誉阈值感知节点恶意行为,进而利用证据理论量化节点信任度,从而检测网络中串谋及独立的恶意节点,为消息选择最优的转发节点。结果表明,在带有串谋的恶意攻击下,所提出的消息转发策略能准确检测出恶意节点,并显著提高消息投递率,改善平均时延。     

无线传感器网络中的路由能耗优化策略的研究

无线传感器网络由于受到实际通信环境的限制,传感节点在进行路由计算与数据转发时所需的电力能源主要由一次性电池供给。为了能够有效的节约节点上的路由能耗,提出了基于网络编码及动态功率控制优化策略,通过优化节点路由的数据转发次数和发射功率,减少了传感节点的路由能耗,延长了网络的生命周期。     

An efficient and intelligent routing strategy for vehicular delay tolerant networks

The vehicular delay-tolerant network is the real-life application based area of Delay tolerant network where communication takes place using vehicular nodes and roadside units. The topology used in vehicular networks is highly dynamic by architecture due to the use of moving vehicular nodes. It operates in such a scenario where a direct path between source and destination remains absent on the most piece of the time. In case of non-existence of connected path vehicular delay-tolerant network works opportunistically and uses the same store, carry, and forward paradigm as Delay Tolerant Network. However, the routing protocols designed for vehicular delay-tolerant network faces crucial challenges like inadequate relay node, incomplete data transfer, a large number of packet drop, and uncertain delivery time. In this research paper, we propose a novel routing strategy for the vehicular delay-tolerant network. The proposed routing strategy selects efficient vehicular relay node for complete packet transfer and intelligently reduces the packet drop for timely packet delivery. We implement the proposed routing strategy in the ONE simulator; the ONE simulator provides an opportunistic environment for nodes. We analyze the performance of the proposed strategy under various simulations results using different parameters. The results show that the proposed strategy outperforms standard routing protocols in terms of considered parameters and provide an efficient solution for the problem of disconnection.

     

一种可容错的覆盖网节点合作激励策略

为了促进覆盖网节点之间的合作,以任意相邻的两个节点为博弈参与者,用纯策略博弈建立了问题模型,证明了静止状态下的节点相互转发博弈是典型的囚徒困境,以及在无限重复囚徒困境博弈情况下,基于针锋相对策略的合作均衡是脆弱的,偶然的网络故障会引发惩罚行为,从而导致节点间的不合作.提出一种可容错的针锋相对策略TTFT（Tolerant Tit-for-tat),使节点能够在一定时间内容忍网络故障的发生.证明了使用该策略可以在发生网络故障的情况下,在有限时间内使节点达到稳定的合作状态,并证明了作弊节点的收益增量相对较低,能够有效降低节点作弊的可能性.模拟试验表明,在多个节点交互的环境下,该策略可以容忍一定比率的故障,促进节点合作,显著提高全体节点的收益总额,并可以降低作弊节点的收益,有效防止作弊.     

Non‐cooperative game‐based packet ferry forwarding for sparse mobile wireless networks

In sparse mobile wireless networks, normally, the mobile nodes are carried by people, and the moving activity of nodes always happens in a specific area, which corresponds to some specific community. Between the isolated communities, there is no stable communication link. Therefore, it is difficult to ensure the effective packet transmission among communities, which leads to the higher packet delivery delay and lower successful delivery ratio. Recently, an additional ferry node was introduced to forward packets between the isolated communities. However, most of the existing algorithms are working on how to control the trajectory of only one ferry work in the network. In this paper, we consider multiple ferries working in the network scenario and put our main focus on the optimal packet selection strategy, under the condition of mutual influence between the ferries and the buffer limitation. We introduce a non‐cooperative Bayesian game to achieve the optimal packet selection strategy. By maximizing the individual income of a ferry, we optimize the network performance on packet delivery delay and successful delivery ratio. Simulation results show that our proposed packet selection strategy improves the network performance on packet delivery delay and successful delivery ratio. Copyright © 2013 John Wiley & Sons, Ltd.     

Dynamic cache allocation routing strategy of Internet of things satellite node based on traffic prediction

Aiming at the routing problem of low earth orbit (LEO) Internet of things (IoT) satellite systems,a dynamic cache allocation routing strategy based on traffic prediction for IoT satellite nodes was proposed.Firstly,the space-time characteristics of traffic distribution in the LEO coverage area were analyzed,and an end-to-end traffic prediction model was proposed.Then,according to the traffic prediction result,a dynamic cache allocation routing strategy was proposed.The satellite node periodically monitored the traffic load of the inter-satellite link,dynamically allocated the cache resources of each inter-satellite link between the neighboring nodes.The cache allocation process was divided into two phases,initialization and system operation.At the same time,the traffic offload and packet forwarding strategy when the node was congested was proposed.By comparing the queuing delay and the forwarding delay,it was determined whether the data packet needs to be rerouted.The simulation results show that the proposed routing strategy effectively reduces the packet loss rate and average end-to-end delay,and improves the traffic distribution in the whole network.     

D2D网络中基于牺牲节点的网络编码协作重传策略

针对D2D无线网络中多终端并发协作重传过程中平均解码时延较高的问题,提出了一种牺牲节点的协作重传策略.在重传阶段,发送终端在立即可解网络编码(Instantly Decodable Network Coding,IDNC)图上根据接收终端与发送终端的链路质量、终端数据包权重和接收终端的连通度选择出发送终端的最优编码包,以降低系统的平均解码时延.同时,利用部分接收终端对最优编码包的无效解码和不可解码的特性,扩展了备选协作终端,使更多的终端参与到协作传输过程.仿真结果表明,所提策略有效降低了系统的平均解码时延和重传次数.     

Scheduling strategy for networked control system based on variable sampling period and deadband feedback

A scheduling strategy of variable sampling period combined with deadband feedback for networked control system is proposed. Variable sampling period algorithm can allocate a reasonable sampling period to each controlled loop according to the network utilization and packet transmission time. Deadband feedback algorithm can alleviate network congestion by appropriately adjusting the packets in the network when the networked control system cannot be scheduled. According to the actual overload and utilization of the network, the designed scheduling strategy dynamically adjusts the sampling period and priority, and improves the performance of the system combined with deadband feedback. Based on the TrueTime platform, the proposed scheduling strategy is verified on a three controlled loops networked control system with interference nodes and limited network resources. The simulation results demonstrate that the designed scheduling strategy can overcome the uncertainty of the upper bound of network resources, improve output control performance, reduce integral absolute error value of the controlled loop, and shorten the packet transmission time. The overall control performance of the system is improved. The designed scheduling strategy is effective.     

用于Ad Hoc网络的多径混合路由

移动Ad hoc网络是由一组移动节点组成的临时网络,它不需要事先建立的网络基础设施的支持。路由协议对网络性能起着决定性的作用。文中提出了一种基于多路径的Ad hoc网络混合路由策略（MPHR）。在MPHR中,边权值表示节点之间的链路可靠性。与传统的单路径路由策略不同,在一对源节点和目的节点间,使用多条路径来发送分组。仿真结果表明,MPHR的分组投递率远高于DSR路由协议,但路由开销略大于DSR。     

Congestion-free communication in high-speed packet networks

The process of packet clustering in a network with well-regulated input traffic is studied and a strategy for congestion-free communication in packet networks is proposed. The strategy provides guaranteed services per connection with no packet loss and an end-to-end delay which is a constant plus a small bounded jitter term. It is composed of an admission policy imposed per connection at the source node, and a particular queuing scheme practiced at the switching nodes, which is called stop-and-go queuing. The admission policy requires the packet stream of each connection to possess a certain smoothness property upon arrival at the network. This is equivalent to a peak bandwidth allocation per connection. The queuing scheme eliminates the process of packet clustering and thereby preserves the smoothness property as packets travel inside the network. Implementation is simple     

A failure detection method for integrated voice/data packetnetworks

A failure detection strategy at the data-link layer, implementable between frame-relay network nodes, is described for integrated voice/data packet networks. This strategy makes it possible to respond to link failures early enough to maintain data-session continuity. A simple, two-phase approach is proposed. In the first phase, the presence of a bit error rate violation along the packet link during short, fixed-length time segments is determined. In the second phase, the failure decision is made on the basis of a sequential algorithm. A simple table lookup implementation of the algorithm that requires no real-time computation is described