Energy considerations for topology-unaware TDMA MAC protocols

Since the energy budget of mobile nodes is limited, the performance of a networking protocol for such users should be evaluated in terms of its energy efficiency, in addition to the more traditional metrics such as throughput. In this paper, two topology-unaware MAC protocols—in which the scheduling time slots are allocated irrespectively of the underline topology—are considered and their energy consumption is derived. It turns out that the per frame power consumption is lower for the less throughput-efficient protocol, suggesting that energy savings are achieved at the expense of throughput.A finer energy consumption study is carried out in the sequel, focusing on the amount of energy consumed to successfully transmit a certain number of packets, or equivalently, on the per successful transmission power consumption. It is shown that the more throughput-efficient protocol consumes less energy per successful transmission under certain conditions (which are derived), due to the lower number of transmission attempts before a data packet is successfully transmitted. The same energy-efficiency relation is observed under certain conditions (which are derived) when data packets are delay constrained and, thus, may become obsolete if not transmitted successfully within a specific time interval. The conditions under which the per successful transmission power consumption is minimized for delay-constrained packets, are also established in this work and it is observed that when the system throughput is maximized, the power consumed is close to the minimum. Simulation results support the claims and the expectations of the aforementioned analysis.     

车联网中基于雾计算和多TA的条件隐私保护认证方案

车联网在生活中扮演着越来越重要的角色,它可以有效地防止交通拥堵从而减少交通事故。然而,在车联网中总是有非法车辆试图接入车联网并发布虚假消息。此外,现有方案多数存在计算效率低下的问题。针对上述存在的问题进行了研究,提出了一种车联网中基于雾计算和多TA的条件隐私保护认证方案。在保护车辆用户身份的条件下实现了车辆、雾节点、TA三者之间的身份认证,且在车辆追踪阶段可以还原车辆用户的真实身份,从而实现条件隐私保护。雾计算的使用降低了方案的计算和通信开销,同时多TA模型的使用也解决了单TA单点故障的问题。安全性证明和性能分析的结果表明该方案是安全且高效的。最后对当前方案进行了总结以及对未来研究作出了展望。     

密集MANET下MPR的改进蚁群优化算法研究

针对传统多点中继（MPR）机制因使用贪心算法而导致求解集合冗余的问题,通过将蚁群优化算法与MPR机制相结合,提出一种基于状态信息的动态更新蚁群优化（DUACO）算法。与传统状态更新机制相比,该算法添加了信息素的动态更新机制和补偿-惩罚规则,考虑到节点移动性将会影响求解集合的精确度,重新定义蚁群算法中的路径选择函数,并将节点移动状态信息加入计算过程。实验结果表明,DUACO算法不仅能够有效降低MPR集合冗余以及提高网络性能,而且还可解决启发式蚁群算法易陷入局部最优解的问题。     

MANET中基于蚁群算法的改进DSR协议*

为提高移动Ad hoc网络中DSR协议的服务质量,提出基于蚁群算法的改进DSR协议---ACOIDSR。ACOIDSR协议路由发现过程中,建立稀疏模式和稠密模式弥补DSR协议泛洪策略的不足;ACOIDSR协议路由选择过程中,利用路径长度、拥塞程度和链接可靠度计算每条路径的信息素数量,进而做出最佳路径的选择;ACOIDSR协议路由维护过程中,提出一种新的信息素衰退策略用于路由维护。最后,仿真实验用于ACOIDSR协议在端到端的延迟、路由负载以及能量消耗等方面分析。     

基于AODV协议的嵌入式自组织平台

无线通信的发展使得Ad-hoc的路由协议受到广泛关注,AODV协议是移动自组织网络中应用最广泛的按需路由协议,能有效的防止路由环路,适用于多种网络拓扑场景。同时,嵌入式开发在移动多媒体平台中起到重要作用,可实现专用、简单、高效的应用层服务平台。本文在基于Linux操作系统的嵌入式平台中搭建了AODV路由协议模块,实现了无线网卡rt3070.ko和自组织路由协议kaodv.ko的交叉编译和移植,验证了嵌入式平台下通过AODV无线路由协议进行组网的可行性和可靠性。通过对相关网络参数的分析,为Ad-Hoc的嵌入式多媒体应用提供了有益参考。     

VANET无线链路质量的测量与分析

目前对移动自组织网络的研究很少涉及现实环境里的测量问题。该文对不同环境下无线链路丢包率、信号强度等参数进行了测量和分析。结果表明,环境对链路质量有较大影响,在郊区环境下,丢包率较低,链路质量较好,信号强度反应链路质量的能力有限,连续丢包概率的变化与丢包率平均值的变化基本一致。分析结果对预测无线链路质量和设计VANET网络协议具有重要意义。     

Fuzzy Fruit Fly Optimized Node Quality-Based Clustering Algorithm for Network Load Balancing

Recently, the fundamental problem with Hybrid Mobile Ad-hoc Networks (H-MANETs) is to find a suitable and secure way of balancing the load through Internet gateways. Moreover, the selection of the gateway and overload of the network results in packet loss and Delay (DL). For optimal performance, it is important to load balance between different gateways. As a result, a stable load balancing procedure is implemented, which selects gateways based on Fuzzy Logic (FL) and increases the efficiency of the network. In this case, since gateways are selected based on the number of nodes, the Energy Consumption (EC) was high. This paper presents a novel Node Quality-based Clustering Algorithm (NQCA) based on Fuzzy-Genetic for Cluster Head and Gateway Selection (FGCHGS). This algorithm combines NQCA with the Improved Weighted Clustering Algorithm (IWCA). The NQCA algorithm divides the network into clusters based upon node priority, transmission range, and neighbour fidelity. In addition, the simulation results tend to evaluate the performance effectiveness of the FFFCHGS algorithm in terms of EC, packet loss rate (PLR), etc.     

Improvisation of Node Mobility Using Cluster Routing-based Group Adaptive in MANET

In today's Internet routing infrastructure, designers have addressed scaling concerns in routing constrained multiobjective optimization problems examining latency and mobility concerns as a secondary constrain. In tactical Mobile Ad-hoc Network (MANET), hubs can function based on the work plan in various social affairs and the internally connected hubs are almost having the related moving standards where the topology between one and the other are tightly coupled in steady support by considering the touchstone of hubs such as a self-sorted out, self-mending and self-administration. Clustering in the routing process is one of the key aspects to increase MANET performance by coordinating the pathways using multiple criteria and analytics. We present a Group Adaptive Hybrid Routing Algorithm (GAHRA) for gathering portability, which pursues table-driven directing methodology in stable accumulations and on-request steering strategy for versatile situations. Based on this aspect, the research demonstrates an adjustable framework for commuting between the table-driven approach and the on-request approach, with the objectives of enhancing the output of MANET routing computation in each hub. Simulation analysis and replication results reveal that the proposed method is promising than a single well-known existing routing approach and is well-suited for sensitive MANET applications.     

无线网络中密钥管理技术概述

密钥管理技术是基本的安全技术之一,在无线网络中扮演重要的角色。无线网络中密钥管理技术的研究是近年来的热点。本文概述了无线网络中密钥管理技术,即无线传感器网络和无线自组网络中的密钥管理技术。     

An ant swarm-inspired energy-aware routing protocol for wireless ad-hoc networks

Primitive routing protocols for ad-hoc networks are “power hungry” and can therefore consume considerable amount of the limited amount of battery power resident in the nodes. Thus, routing in ad-hoc networks is very much energy-constrained. Continuous drainage of energy degrades battery performance as well. If a battery is allowed to intermittently remain in an idle state, it recovers some of its lost charge due to the charge recovery effect, which, in turn, results in prolonged battery life.In this paper, we use the ideas of naturally occurring ants’ foraging behavior (Dorigo and Stuetzle, 2004) [1] and based on those ideas, we design an energy-aware routing protocol, which not only incorporates the effect of power consumption in routing a packet, but also exploits the multi-path transmission properties of ant swarms and, hence, increases the battery life of a node. The efficiency of the protocol with respect to some of the existing ones has been established through simulations. It has been observed that the energy consumed in the network, the energy per packet in the case of EAAR are 60% less compared to MMBCR and the packets lost is only around 12% of what we have in AODV, in mobility scenarios.