Collaboration of Trusted Node and QoS Based Energy Multi Path Routing Protocol for Vehicular Ad Hoc Networks

In the recent past information transmission through the vehicular ad hoc network (VANET) playing a vital role due to increase in accident statistics. There are numerous networking and VANET protocols helpful to control the trust while transmitting the data from source to destination nodes in traffic environment. In spite of many existing protocols for analyzing the trust in the network, the challenge of routing overhead, high energy consumption and malicious attacks issues still continue in the communication. This research introduces the trust collaboration nodes and Quality of Service (QoS) with energy multipath routing protocol for transmitting the information through VANET. Initially, the trusted nodes have been collected for analyzing the neighbouring nodes and the information are transmitted using the proposed QoS based energy efficient multipath routing protocol. During this transmission, the multi path protocol eliminates the intermediate attacks effectively when compared with the other existing protocols. The Proposed protocol maintains the QoS while routing the information from source to destination and further the efficiency has been analyzed through simulation experiments and Montgomery multiplier based Elliptic Curve Cryptography (ECC) will be used in future for better security and privacy.     

多径环境下异步长码直接序列码分多址信号伪码序列及信息序列盲估计

针对低信噪比 (SNR)下存在多径效应的传统单通道异步长码直接序列码分多址(DS-CDMA)信号伪码序列(PN)及信息序列难估计问题,该文提出一种基于平行因子的多通道盲估计方法。该方法先将接收到的多径信号建模为多通道模型,然后将长码DS-CDMA信号建模成短码DS-CDMA信号的缺失数据模型,形成观测缺失数据矩阵,并将其等效为缺失平行因子模型,最后利用正则交替最小二乘法(ALS)对缺失平行因子进行低秩分解,实现多径环境下长码DS-CDMA信号各用户伪码序列及信息序列的盲估计。仿真结果表明,序列的估计性能与多径环境密切相关,且在莱斯因子为10,多径路数为3,通道数为4,用户数为6,信噪比大于–10 dB的条件下,伪码序列及信息序列的估计错误率均低于1%。     

基于相似性传播的天波雷达多路径量测聚类

电离层多层结构特性使得天波雷达(OTHR)与目标之间存在多条信号传播路径,进而可能对单目标产生多路径量测。该文考虑了天波雷达多路径量测聚类问题,其需要同时对多路径量测进行电离层传播路径辨识和聚类。由于天波雷达量测模型假设1个目标通过1种电离层传播路径至多产生1个量测,因此需要考虑多路径聚类约束。该文将相似性传播聚类扩展到多路径约束模型,并提出一种新的多路径相似性传播聚类算法。该算法通过构建多路径量测聚类的概率图模型,将聚类问题转化为概率图模型隐变量的推断问题,采用最大和置信传播算法近似求解聚类变量的最大后验概率。算法优点包括可以自动识别聚类团数目,单次消息传播的时间复杂度为量测个数和传播路径个数乘积的平方。仿真实验分析表明,所提算法较多路径多假设聚类算法具有更好的聚类性能。     

面向关联属性的差分隐私信息熵度量方法

针对差分隐私非交互式多属性关联的合成数据集发布问题,基于信息熵、汉明失真提出了发布数据集隐私度、数据效用、隐私泄露风险的量化方法.首先,利用互信息量分析属性相关度,并以关联依赖图模型表达属性关联.其次,基于图中关键隐私泄露路径构建马尔可夫隐私泄露链,并结合信息熵提出一种关联属性隐私度量模型及方法,可以有效的度量由关联属性引起的隐私泄露量.最后,通过具体实例验证了模型与方法的有效性,并对比分析了该方法的优势.     

Concurrent multipath traffic impersonating for enhancing communication privacy

Network communication traditionally only uses encryption techniques for privacy and a single path for routing, which makes the communication vulnerable to attackers. Attackers easily obtain much important information by eavesdropping on the path and analyzing the communication traffic. To overcome the problem, we propose concurrent multipath traffic impersonating (CMTI), which obscures traffic features by camouflaging the traffic flow and dividing it into multiple parts. We propose a traffic impersonating technique based on statistical simulation, which make the secret traffic look like another normal and inconspicuous class to deceive attackers. And we present the packet scheduling algorithm to transfer the impersonating flows on multipath, for enhancing the communication efficiency and further increasing significantly the cost inflicted on attackers who wish to eavesdrop communication sessions. The empirical analysis demonstrates that concurrent multipath traffic imitating can effectively thwart traffic analysis and enhance communication efficiency. Copyright © 2013 John Wiley & Sons, Ltd.     

Considerations for application‐layer multipath transport control

Multipath transport faces a lot of challenges caused by path diversity, network dynamics, and service diversity. An effective end‐to‐end multipath transport control mechanism becomes essential to efficiently utilize multiple paths. On the base of the general framework of multipath transport system based on application‐level relay proposed in our previous work, this paper presents a multipath transport control mechanism supporting various applications with different transmission requirements. We propose a multipath transport protocol suite, which is extensible and suitable for various applications, and a multipath transport control model in which an application‐dependent splitting granularity named flow block is introduced. Two load distribution models are explored: the earliest idle path first load distribution for reliable data transmission to maximize the data throughput and the packet reordering‐controlled load distribution for real‐time data transmission to minimize the packet reordering thereby reducing end‐to‐end delay and packet loss rate of multipath transport. Simulation results show that the proposed models can effectively improve data throughput for applications with reliable transmission requirements and reduce the total packet loss rate of the destination for applications with real‐time transmission requirements.     

Adaptive Echo Cancellation Based on a Multipath Model of Acoustic Channel

Usually Acoustic Echo Cancellers (AECs) are realized by adaptive Finite duration Impulse Response (FIR) filter having large number of coefficients and Least Mean Square (LMS) as an adaptive algorithm resulting in slow convergence speed and poor tracking performance of these adaptive filters. In this paper, we have proposed a Multiple Sub-filter (MSF) parallel structure based on multipath acoustic echo model using the basis that each sub-filter will compensate the echo contributed by each path of multipath acoustic channel. To realize the MSF, modified Generalized Autocorrelation-based Estimator (MAE) has been used to estimate time delay associated with each path while the order of each sub-filter has been estimated using Power Spectral Density (PSD) method. Accuracy Percentage (AP) performance measure has been used to characterize the performance of the estimator. Simulation results show that the performance of the MAE improves with the increase in SNR and/or decrease in number of multipath. Using these estimates MSF based AEC is constructed. The convergence performance of MSF-based AEC has been studied, via computer simulation, and compared with the conventional Single Long length adaptive Filter (SLF)-based canceller for different SNRs and number of multipath. The results of MSF have been found to be very encouraging in almost all of the various situations considered. Subsequently, the tracking behavior has also been studied with variation in the channel parameters of the multipath model. The proposed MSF can track variations in the channel parameters of the multipath model faster as compared to the conventional echo canceller.     

基于位置感知和代理的WSN多径路由方案

针对无线传感器网络(WSN)中多径路由的可靠性和能量效率问题,提出了一种基于代理和位置感知的多径路由发现方案(LABMR).事件节点根据位置信息,动态寻找其到Sink节点之间的特殊中间节点,来构建多径路由.利用移动代理来收集多径路由的局部拓扑结构信息,Sink节点根据代理收集的路由参数来计算路径权值,以此选择最优不相交路径.同时,对于信息的重要性差异,Sink节点选择单条或多条路径来传输数据,在保证传输可靠性的同时减少能耗.与现有的基于代理的多径路由(ABMR)方法相比,LABMP在数据包投递率、能量消耗、额外开销和延迟方面具有更好的性能.     

Load balancing maximal minimal nodal residual energy ad hoc on-demand multipath distance vector routing protocol (LBMMRE-AOMDV)

Mobile ad hoc multipath routing protocols have attracted considerable research attention over the past decade, but the limited battery life of nodes remains a significant obstacle. Many researchers have designed multipath routing protocols that balance the data load between the generated paths, but there is always some tradeoff between conserving the nodes’ energy and delivering data. In this paper, I introduce a load balancing (LB) multipath routing protocol based on maximal minimal nodal residual energy (MMRE) in the ad hoc on-demand multipath distance vector (AOMDV) protocol. The proposed LBMMRE-AOMDV protocol evaluates the generated paths based on the maximal nodal residual energy and the actual number of packets that could be transmitted over that path without depleting the nodes’ energy. The performance of the proposed protocol was tested and evaluated using different scenarios and performance metrics, and achieved good results compared with MMRE-AOMDV and AOMDV. In particular, the proposed method can increase packet delivery and decrease the number of dead nodes, thus reducing the probability of network portioning.