一种应用于WBAN的动态自适应网络研究

基于WBAN的技术尚不成熟,提出一种新型WBAN技术方案,将HBC技术与MICS频段结合应用到WBAN中.考虑到体域网中体内节点的能耗约束性,提出了一种应用于WBAN的新型网络,即具有自适应性的基于中继的两跳星型网络;针对WBAN中节点生存周期的重要性,提出一种低能耗的MAC协议——基于TDMA的中继MAC协议.该方案的提出,能够满足WBAN对安全、能耗、可靠性等服务质量(QoS)的要求,且较好地改善了体内节点的网络生存期.     

基于拓扑优化和链路感知的无线体域网路由协议

为解决无线体域网(Wireless Body Area Networks,WBAN)在人体运动过程中网络拓扑结构频繁变化导致链路质量和WBAN性能下降等问题,首先根据人体结构对WBAN网络拓扑进行优化,通过添加中继节点建立WBAN主干网,提供节点和hub之间相对稳定的链接,然后提出了适用于WBAN拓扑优化后的路由策略(Routing Protocol Based on Topology Optimization and Link Awareness,R-TOLA)。R-TOLA综合了链路质量感知和代价函数,通过调整主干网中继和节点中继获得最优化路径。仿真实验表明,基于拓扑结构优化和链路感知的R-TOLA协议和其他路由协议相比,在人体拓扑网络结构频繁变化的环境下具有网络生存时间更长、吞吐量更大等优势。     

具有路径能耗优化特性的WSN无标度容错拓扑控制算法

针对数据传输型的大规模无线传感网络中路径能量损耗问题,建立在多跳模式下的网络路径能耗优化模型,得出可以使网络通信能耗最小的节点度取值规律。依据节点度的最优取值,通过控制网络平均节点度的适应度模型来构建网络拓扑,提出一种具有路径能耗优化特性的无标度容错拓扑控制算法EETA(energy efficiency topology algorithm)。动态性能分析表明,由该算法生成的网络拓扑,其节点的度分布服从幂律,具有无标度拓扑的强容错能力。仿真实验结果显示,该算法同时也降低了网络路径能量消耗,具有路径节能性。     

基于临时节点的无线体域网高效节能路由算法

以优化网络路由、延长网络生存期为目的,提出了一种基于临时节点的无线体域网(Wireless Body Area Network,WBAN)高效节能路由算法-A WBAN Efficient Energy-saving Routing Scheme Utilizing Temporary Nodes(RSUTN).该算法针对WBAN应用中出现的新的情况,通过充分利用临时节点富余能量,优化网络路由,平衡网络节点间能量消耗,延长网络生存期.理论分析和仿真结果表明,该算法能明显地平衡网络能量消耗,显著地延长网络生存期.     

基于稀疏表示的体域网节点休眠策略

针对无线体域网(WBAN)节点电池能量有限和不易更换电源的问题,提出一种基于稀释表示分类算法的节点休眠策略(NSS-SRC)。当WBAN节点采集的人体生理信号处于正常范围时,采用稀疏表示理论对测试样本信号进行识别,根据识别结果滤除不需要传送的正常信号,将WBAN节点转换为休眠状态,并延长节点休眠时间,从而减少节点数据传输量。通过NS2软件对节点延时和能耗进行仿真分析,结果表明,在生理信号通常处于稳定范围的WBAN中,与传统TDMA,BCMAC相比,NSS-SRC策略能有效降低能耗和延时。     

基于改进NSGA-Ⅱ的移动汇聚异构WSN多目标优化

阐述无线传感网络中多sink节点调度,提出多目标优化的移动汇聚节点调度模型,改进NSGA-Ⅱ算法。该模型以能耗最小以及覆盖率最大作为优化目标,通过预测节点寿命来构筑新的目标函数,对节点死亡轮数进行聚类并以此为基础进行汇聚节点移动调度,减少了网络拓扑结构变化带来的影响。     

基于人工蜂群寻优算法的WSN中继节点布局方案

无线传感器网络(WSN)环境下,中继节点位置布局性能优劣是影响网络寿命的关键因素之一。目前,针对三维空间高密度WSN,缺少能够在硬件成本和连通性双重约束条件下提高网络寿命的中继节点位置布局方案。基于网格布局方式,提出了一种基于人工蜂群优化算法的中继节点布局方案(ABC-RNDS)。ABC-RNDS方案采用双层网络拓扑结构,首先使用最小生成树法构建骨干网络,再使用人工蜂群优化算法通过网络参数寻优和限制中继节点总数的方法实现网络寿命的延长。实验验证分析表明,在成本和连通性受约束的条件下,ABC-RNDS算法与传统方案相比能够显著提高网络寿命。     

基于代数连通度优化的空间信息网络分布式拓扑控制方法

针对空间信息网络中节点高速运动导致的网络拓扑结构难以长期稳定的问题,本文提出了基于代数连通度优化的网络动态拓扑控制方法,通过少量链路调整来维持网络拓扑的稳定性.为减小空间信息网络节点持续相对运动对网络拓扑结构稳定性造成的不利影响,针对网络初始化和网络重构场景,采用图论中的拉普拉斯矩阵特征值优化思想,构建了星上资源约束条件下的加权代数连通度最大化模型.为降低计算复杂度来实现网络拓扑的捷变控制,提出了基于连通矩阵弱摄动的动态网络拓扑控制策略.研究结果表明,提出的算法能够通过内点法,可高效地得到次优解,且次优解与全局最优解十分接近.     

基于能效优化的WSNs多径流量分配路由算法

该文针对传感器节点能量受限的特点建立能效优化模型,该模型兼顾网络传输能耗和能耗均衡特性,以最大化网络节点总剩余能量和最小化剩余能量的方差为目标,通过合理分配多条路径的流量来优化网络能效。利用权衡评价函数实现了模型的求解,进而提出一种多径流量分配路由(MFAR)算法。仿真实验表明,该算法能够合理配置各路径流量,显著提高网络能量效率,达到在降低网络能耗的同时保证能耗分布均衡的目标。     

基于稳定链路的WSNs拓扑优化算法设计及仿真研究

无线传感器网络在物联网中占有重要地位,其能够降低能耗并有效保障数据传输。然而,无线传感器网络底层拓扑结构通常存在网络链路质量低、网络能耗高、网络干扰等问题。针对现有网络链路不稳定的问题,提出具有稳定链路的幂律可调优化算法,并对其生成的拓扑动态性能进行研究。通过网络节点失效容错需求仿真和链路稳定性仿真,验证了幂律可调优化算法的准确性,为无线传感器网络拓扑优化提供参考。     

基于约束路由的绿色虚拟拓扑设计算法

摘 要：针对Internet核心网日益严重的能耗问题,建立了绿色虚拟拓扑设计(GVTD)问题的形式化模型,通过业务汇聚、按需配置网络资源、动态虚拟拓扑设计和多粒度睡眠机制降低网络能耗。提出了一种基于约束路由的启发式算法——CBR-GVTD算法,利用单跳路由和多跳路由相结合的方法构建网络虚拟拓扑,并通过基于约束的路由实现网络功耗与路由性能的折衷。模拟结果表明,CBR-GVTD算法可在接口平均利用率为80%~90%和最大路由跳数不超过5的条件下,最多可降低62%~90%的网络功耗     

一种能量平衡的无线体域网络AODV多播路由发现协议

在动态网络拓扑中,AODV协议通过数据源节点S泛洪广播RREQ消息请求到任意目标节点D的路由,而在无线体域网络中,只有一个sink目标节点,除最短跳数路由上的节点外,其他参与RREQ接收和转发的节点浪费了能量。提出了一种能量平衡的无线体域网络AODV多播路由发现协议,通过在节点广播的hello消息中增加到sink的最小跳数hops、到sink的下一跳节点next和节点本身是否具备转发能力isforward 3 个参数,只选择能到达sink节点的邻居节点参与转发RREQ消息,变广播为多播,有效地降低了路由发现的能量开销,并通过能量平衡延长了WBAN的使用寿命。性能分析与模拟实验表明,该协议在RREQ数量、数据传输率和能量消耗等方面优于相似协议EAAODV。     

Energy‐Connectivity Tradeoff through Topology Control in Wireless Ad Hoc Networks

In this study, we investigate topology control as a means of obtaining the best possible compromise between the conflicting requirements of reducing energy consumption and improving network connectivity. A topology design algorithm capable of producing network topologies that minimize energy consumption under a minimum‐connectivity constraint is presented. To this end, we define a new topology metric, called connectivity efficiency, which is a function of both algebraic connectivity and the transmit power level. Based on this metric, links that require a high transmit power but only contribute to a small fraction of the network connectivity are chosen to be removed. A connectivity‐efficiency‐based topology control (CETC) algorithm then assigns a transmit power level to each node. The network topology derived by the proposed CETC heuristic algorithm is shown to attain a better tradeoff between energy consumption and network connectivity than existing algorithms. Simulation results demonstrate the efficiency of the CECT algorithm.     

SDN‐based wireless body area network routing algorithm for healthcare architecture

The use of wireless body area networks (WBANs) in healthcare applications has made it convenient to monitor both health personnel and patient status continuously in real time through wearable wireless sensor nodes. However, the heterogeneous and complex network structure of WBANs has some disadvantages in terms of control and management. The software‐defined network (SDN) approach is a promising technology that defines a new design and management approach for network communications. In order to create more flexible and dynamic network structures in WBANs, this study uses the SDN approach. For this, a WBAN architecture based on the SDN approach with a new energy‐aware routing algorithm for healthcare architecture is proposed. To develop a more flexible architecture, a controller that manages all HUBs is designed. The proposed architecture is modeled using the Riverbed Modeler software for performance analysis. The simulation results show that the SDN‐based structure meets the service quality requirements and shows superior performance in terms of energy consumption, throughput, successful transmission rate, and delay parameters according to the traditional routing approach.     

绿色通信网的设计分析

网络节能在无线网络中已经有了很多的研究,并已经取得了很好的成果,本文从有线网络的角度首先分析了有线网络现状,然后从单个交换设备、网络级和拓扑级分析可能的节能基点,并建议从网络设计、系统设计和协议设计3方面注重能量意识从而达到节能效果。最后从主要的休眠技术出发分析了节能可能对OSPF等路由协议和网络拓扑影响,从软件和硬件方面对现有的网络和拓扑稍加改变将会达到很好的节能效果。     

Proposal of a hierarchical topology and spatial reuse superframe for enhancing throughput of a cluster‐based WBAN

A cluster topology was proposed with the assumption of zero noise to improve the performance of wireless body area networks (WBANs). However, in WBANs, the transmission power should be reduced as low as possible to avoid the effect of electromagnetic waves on the human body and to extend the lifetime of a battery. Therefore, in this work, we consider a bit error rate for a cluster‐based WBAN and analyze the performance of the system while the transmission of sensors and cluster headers (CHs) is controlled. Moreover, a hierarchical topology is proposed for the cluster‐based WBAN to further improve the throughput of the system; this proposed system is called as the hierarchical cluster WBAN. The hierarchical cluster WBAN is combined with a transmission control scheme, that is, complete control, spatial reuse superframe, to increase the throughput. The proposed system is analyzed and evaluated based on several factors of the system model, such as signal‐to‐noise ratio, number of clusters, and number of sensors. The calculation result indicates that the proposed hierarchical cluster WBAN outperforms the cluster‐based WBAN in all analyzed scenarios.     

TinyZKP: A Lightweight Authentication Scheme Based on Zero-Knowledge Proof for Wireless Body Area Networks

Secure communication over wireless body area network (WBAN) is a key issue in the design and deployment of WBAN systems, in which the authentication of sensor node is a critical process. Conventional authentication schemes are not suitable to the sensor node because of the limitations of memory, computational power and energy in the node. In order to provide an efficient method to verify the identity of sender sensor nodes of WBAN, in this paper a lightweight authentication scheme, TinyZKP, based on zero-knowledge proof (ZKP) is proposed and implemented on TinyOS-based sensor nodes. Our experimental results show that, compared to two ECDSA-based authentication schemes in TinyECC and WM-ECC, the TinyZKP runs 1.9 and 1.4 times faster and the energy cost is reduced by 48 % and 28 %, respectively.     

基于局域偏好的移动自组织网络演进模型

To accurately describe the evolving features of Mobile Ad Hoc Networks (MANETs) and to improve the performance of such networks, an evolving topology model with local-area preference is proposed. The aim of the model, which is analyzed by the mean field theory, is to optimize network structures based on users’ behaviors in MANETs. The analysis results indicate that the network generated by this evolving model is a kind of scale-free network. This evolving model can improve the fault-tolerance performance of networks by balancing the connectivity and two factors, i.e., the remaining energy and the distance to nodes. The simulation results show that the evolving topology model has superior performance in reducing the traffic load and the energy consumption, prolonging network lifetime and improving the scalability of net-works. It is an available approach for estab-lishing and analyzing actual MANETs.     

Efficient Patient Care Through Wireless Body Area Networks—Enhanced Technique for Handling Emergency Situations with Better Quality of Service

Wireless body area networks (WBAN) is a wireless network of sensors placed in and around the human body for monitoring the patient conditions remotely. The goal of WBAN networks is to report the patient condition to the monitoring system with maximum reliability and minimum delay and deliver the life critical data in the emergency situation with utmost priority. The proposed MAC protocol is aimed at delivery of emergency packets with maximum reliability and minimum delay through the introduction of mini slots in the beacon enabled superframe for exclusive transmission of the same. To improve the packet delivery ratio of the normal packets and decrease the energy consumption of the low data rate nodes, a packet rate based scheduled slot allocation is added to this protocol. Extensive simulations show that the proposed protocol is able to achieve nearly 98% packet delivery ratio and less than 100 ms delay for emergency packets. By varying the number of allocated scheduled slots based on the packet rate of the nodes, the proposed protocol has shown improved performance in the packet delivery ratio (93%) of normal packets as compared to IEEE 802.15.6 (85%), also the energy consumption of low data rate nodes has decreased by 64%. The results show that the proposed protocol is successful in realizing much better delay and packet delivery values for emergency and normal packets.