A Distributed Virtual Backbone Formation for Wireless Ad Hoc and Sensor Networks

The virtual backbone is an approach for solving routing problems in wireless ad hoc and sensor networks. A connected dominating set (CDS) was proposed as a virtual backbone to improve the performance of wireless networks. The quality of a virtual backbone is measured not only by approximation factor, which is the ratio of its size to that of minimum CDS, but also time complexity and message complexity. In this paper, a distributed algorithm is presented to construct a minimum CDS for ad hoc and sensor networks. By destroying triangular loops in the virtual backbone, the proposed algorithm can effectively construct a CDS with smaller size. Moreover, our algorithm, which is fully localized, has a constant approximation ratio, linear message and time complexity, and low implementation complexity. The simulation results and theoretical analysis show that our algorithm has better efficiency and performance than conventional approaches.

Energy-efficient low-latency virtual cluster synchronization algorithm based on SMAC protocol in wireless sensor networks

The MAC protocol design for wireless sensor networks has been researched and developed for decades. SMAC protocol is a famous energy-efficient MAC protocol. Based on SMAC protocol, we find that the boundary nodes in the cluster-shaped synchronization structure bring energy consumption seriously, and provide a virtual cluster aggregation (VCA) algorithm. Because the bounder node follows multiple schedules in one cycle, it may deplete earlier and cause segmentation in wireless sensor networks. The algorithm reduces energy consumption of boundary nodes and extends the lifetime of entire sensor network by merging different virtual clusters, but increases the data transmission delay. Because the sensor nodes have the fixed duty cycle, the larger the coverage area of network is, the greater the data transmission delay increases. We propose the dynamic duty cycle (DDC) algorithm to solve this effect. When the network load and data transmission delay increase, the DDC algorithm exponentially changes the duty cycle of the node to reduce latency. The simulation results show that the performance of SMAC with the VCA and DDC algorithm obtains improvement significantly.

Essential Topics on Constructing WCDS-based Virtual Backbone in Wireless Sensor/Mesh Networks

Clustering or connected dominating set (CDS) both approaches can establish a virtual backbone (VB) in wireless sensor networks (WSNs) or wireless mesh networks (WMNs). Each cluster consisting of a cluster head (CH) and its neighboring nodes can form a dominating set. After some bridging nodes were selected, cluster heads (CHs) connected through these bridging nodes naturally formed a CDS. Although CDS provides obvious backbone architecture, however, the number of cluster heads and bridging nodes may be too large, this may cause the loss of advantages of virtual backbone. When we effectively reduce their numbers, more effectively WCDS (Weakly Connected Dominating Set) can be fining out. Some essential topics on constructing WCDS-based VB in WSN/WMN are discussed in this paper. From the point of view of three different protocol layers, including network (NWK) layer, MAC layer, and physical (PHY) layer, we explore their cross-layer research topics and design algorithms. For NWK layer, area-based WCDS algorithms and routing strategies including via VB and not via VB are discussed. For MAC layer, a WCDS-based energy-efficient MAC protocol is presented. For PHY layer, battery-aware alternative VB selections and sensor nodes with different transmission ranges are addressed.

A Cooperative MIMO Transmission Scheme for Cluster-based Wireless Sensor Networks

Wireless sensor network is becoming more and more popular in recent years, but energy- constrained characteristic of sensor nodes is one of the critical issues that we must consider in system design. In this paper, a cluster-based virtual VBLAST transmission scheme is proposed to achieve energy savings for energy-constrained wireless sensor networks. In the proposed scheme, instead of using cluster member as cooperative nodes, multiple cluster heads cooperate to form virtual antenna array so that V-BLAST based virtual MIMO transmission can be implemented. Based on the communication energy consumption model, a way to optimize the parameters for the scheme is given. In addition, detailed simulation is performed to evaluate the performance of the proposed scheme for both densely and sparsely deployed sensor networks. Theoretical analysis and simulation results verify the energy efficiency of the proposed scheme.

Energy-Efficient Transmission Scheme for Mobile Data Gathering in Wireless Sensor Networks

Energy conservation in Wireless Sensor Networks (WSNs) has always been a crucial issue and has received increased attention in the recent years. A transmission scheme for energy-constrained WSNs is proposed in this paper. The scheme, called MIHOP (MIMO and Multi-hop), combines cluster-based virtual MIMO and multi-hop technologies. The multihop mode is employed in transmitting data when the related sensors are located within a specific number of hops from the sink, and the virtual MIMO mode is used in transmitting data from the remaining sensor nodes. We compare the energy consumption of different transmission schemes and propose an algorithm for determining the optimal hop count in MIHOP. A controllable mobile sink that reduces the energy consumed in sensor transmission is also adopted for data collection. The theoretical analysis and the Monte Carlo simulation demonstrate that the proposed scheme significantly outperforms individual virtual MIMO, multi-hop technologies, and double-string networks in terms of energy conservation. The energy consumption levels under the MIHOP scheme are approximately 12.98%, 47.55% and 48.30% less than that under virtual MIMO schemes, multi-hop networks and doublestring networks, respectively.

A New Distributed Localization Scheme for Wireless Sensor Networks

在无线传感器网络(WSN ) 的节点本地化是被对待一功能目标在纸从一个新奇观点追踪双。与在 WSN 的传统的追踪问题不同，使用静态的地点商品节点估计动人的目标，活动节点被用来帮助未知节点精确地发现他们的位置。一个新节点本地化计划虚拟烽火精力比率本地化(VB-ERL ) 和它为 WSN 的精炼被介绍。在计划，活动节点基于 Gauss-Markov 活动性模型搬到监视者地并且周期性地广播信息包。每个静态的未知节点在它的察觉到的范围收到虚拟烽火和精力，并且由发现一套超球面的交叉估计它的地点。模拟结果证明建议计划是有效的。

Lifetime Optimization via Network Sectoring in Cooperative Wireless Sensor Networks

Employing cooperative communication in multihop wireless sensor networks provides the network with significant energy efficiency. However, the lifetime of such a network is directly dependant upon the lifetime of each of its individual sections (or clusters). Ignoring the fact that those sections close to sink have to forward more data (their own data plus the data received from the previous sections) and hence die sooner with considering equal section sizes, leads to a sub-optimal lifetime. In this paper, we optimize the section sizes of a multihop cooperative WSN so that it maximizes the network lifetime. Simulation results demonstrate a significant lifetime enhancement for the proposed optimal sectoring.

A Sensor Awakening Algorithm for Wireless Multimedia Sensor Networks Three Dimensional Target Tracking

For node awakening in wireless multi-sensor networks, an algorithm is put forward for three dimensional tar- get tracking. To monitor target dynamically in three dimensional area by controlling nodes, we constract vir- tual force between moving target and the current sense node depending on the virtual potential method, then select the next sense node with information gain function, so that when target randomly move in the specific three dimensional area, the maximum sensing ratio of motion trajectory is get with few nodes. The proposed algorithm is verified from the simulations.

A Void Avoidance Scheme for Grid-Based Multipath Routing in Underwater Wireless Sensor Networks

This work proposes a geographic routing protocol for UWSNs based on the construction of a 3D virtual grid structure, called Void-Avoidance Grid-based Multipath Position-based Routing (VA-GMPR). It consists of two main components, the multipath routing scheme and the grid-based void avoidance (GVA) mechanism for handling routing holes. The multipath routing scheme adopts node-disjoint routes from the source to the sink in order to enhance network reliability and load balancing. While the GVA mechanism handles the problem of holes in 3D virtual grid structure based on three techniques: Hole bypass, path diversion, and path backtracking. The performance evaluation of the VA-GMPR protocol was compared to a recently proposed grid-based routing protocol for UWSNs, called Energy-efficient Multipath Geographic Grid-based Routing (EMGGR). The results showed that the VA-GMPR protocol outperformed the EMGGR protocol in terms of packet delivery ratio, and end-to end-delay. However, the results also showed that the VA-GMPR protocol exhibited higher energy consumption compared to EMGGR.

A movement-assisted software-defined sensor network with NFV support

A flexible and controllable movement-assisted software-defined sensor network(MA-SDSN)based on the software-defined network(SDN)and network function virtualization(NFV)is proposed.First,a three-layer fundamental architecture is proposed to overcome the inherent distributed management and rigidity of the conventional wireless sensor networks.Furthermore,the platform for research and development of MA-SDSN is established,and the dumb node(DN),the software-defined node(SN)and the movement-assisted node(MN)are designed and implemented.Then,the southbound application programming interface(API)is designed to provide a series of frames for communication between controllers and sensor nodes.The northbound API is developed and demonstrated overall and in detail.The functions of the controller are presented including topology discovery,dynamic networking,packet processing,mobility management and virtualization.Followed by the MA-SDSN network model,a Markov chain-based movement-assisted weighted relocation(MMWR)topology control algorithm is proposed to redeploy the MNs based on the node status and weight.Simulation results and analysis indicate that the proposed algorithm based on the MA-SDSN extends network lifetime with a lower average power consumption.

Smart Body Sensor Object Networking

This paper discusses smart body sensor objects （BSOs）, including their networking and internetworking. Smartness can be incorpo-rated into BSOs by embedding virtualization, predictive analytics, and proactive computing and communications capabilities. A few use cases including the relevant privacy and protocol requirements are also presented. General usage and deployment eti-quette along with the relevant regulatory implications are then discussed.

Body Worn Sensors for Health Gaming and e-Learning in Virtual Reality

Virtual reality is an emerging field in the whole world.The problem faced by people today is that they are more indulged in indoor technology rather than outdoor activities.Hence,the proposed system introduces a fitness solution connecting virtual reality with a gaming interface so that an individual can play first-person games.The system proposed in this paper is an efficient and cost-effective solution that can entertain people along with playing outdoor games such as badminton and cricket while sitting in the room.To track the human movement,sensors Micro Processor Unit(MPU6050)are used that are connected with Bluetoothmodules andArduino responsible for sending the sensor data to the game.Further,the sensor data is sent to a machine learning model,which detects the game played by the user.The detected game will be operated on human gestures.A publicly available dataset named IM-Sporting Behaviors is initially used,which utilizes triaxial accelerometers attached to the subject’s wrist,knee,and below neck regions to capture important aspects of human motion.The main objective is that the person is enjoying while playing the game and simultaneously is engaged in some kind of sporting activity.The proposed system uses artificial neural networks classifier giving an accuracy of 88.9%.The proposed system should apply to many systems such as construction,education,offices and the educational sector.Extensive experimentation proved the validity of the proposed system.

Calculation of Minimal Dominating Set in Wireless Sensor Network with Host Switch-on/off

This paper proposes a simple and efficient distributed algorithm for calculating minimal dominating set in wireless sensor network. This method can avoid maintaining the connectivities between backbone hosts. Considering that the hosts in mobile networks have different characteristics, this paper proposes a method of calculating minimal dominating set with weight. The nodes can be chosen to form a minimal dominating set when the network topology changes. For the host switch on/off operation, the updating algorithm was provided. The change in the status of a hostaffects only the status of hosts in the restricted vicinity. Simulation results show that the proposed method can ensure fewer dominators but with higher weight to form the minimal dominating set and the nodes can be adaptive to the changes of network topology.

Dynamic coverage of mobile multi-target in sensor networks based on virtual force

A distributed self-control coverage method for mobile multi-target based on virtual force(MMTVF)is proposed to monitor dynamic targets using a mobile sensor network(MSN).The dynamic coverage method is introduced to maintain network connectivity and optimize the coverage of moving targets.The method consists of two parts,one is the virtual force model which is proposed for motion control,and the other is the whale optimization algorithm which is improved to optimize node positions and achieve a steady state quickly.The virtual resultant force stretches the network towards uncovered targets using its multi-target attractive force,maintains network connectivity during network stretching using its attractive force,and prevents node collisions while nodes are moving using its repulsive force.The operating mechanism of the multi-target attractive force and other forces is thoroughly analyzed.Adjustment criteria for the model in different application scenarios are also provided.The comparisons demonstrate MMTVF has significant advantages over other similar approaches.

Designing reduced beacon trajectory for sensor localization

Localization is one of the substantial issues in wireless sensor networks. The key problem for the mobile beacon localization is how to choose the appropriate beacon trajectory. However, little research has been done on it. In this paper, firstly, we deduce the number of positions for a beacon to send a packet according to the acreage of ROI (region of interest); and next we present a novel method based on virtual force to arrange the positions in arbitrary ROI; then we apply TSP (travelling salesman problem) algorithm to the positions sequence to obtain the optimal touring path, i.e. the reduced beacon trajectory. When a mobile beacon moves along the touring path, sending RF signals at every position, the sensors in ROI can work out their position with trilateration. Experimental results demonstrate that the localization method, based on the beacon reduced path, is efficient and has flexible accuracy.

无线地下传感网信道传播实验虚拟仿真与可视化教学

为帮助学生更好地理解和掌握无线地下传感网信道传播特性,推导并建立一个融合土壤特性参数的改进地下无线信道传播模型,在该模型基础上开发无线地下传感网实验虚拟仿真系统。该仿真系统不仅解决实验环境受限、难以开展实验教学的问题,且具有易于理解和操作的特点,仿真结果以图形化和可视化的形式呈现。通过此系统,学生可直观地观察和比较不同参数影响下地下无线信道传播变化情况,深入理解地下无线信道的复杂传播特性,提高学生的学习效率,激发学生的学习兴趣,促进学生学习的主动性和积极性。

无线传感器网络中基于量子郊狼优化的分簇路由协议

为进一步均衡无线传感器网络能耗,延长网络寿命,本文提出了一种基于量子郊狼优化的分簇路由协议。基于量子郊狼优化的分簇路由协议服务于静态部署网络,使用结合量子计算与郊狼优化算法优势的量子郊狼优化动态集中式搭建簇,并在簇有效期内综合考虑传感器能量、到基站距离和到虚拟簇首距离3种因素动态分布式轮换簇首,再通过簇首本地广播的形式动态分布式搭建数据中继传输链。仿真结果表明:与分布式低能耗自适应集群层次协议、基于粒子群优化模糊C均值的分簇路由算法和能量有效非均匀分簇路由协议相比,基于量子郊狼优化的分簇路由协议能有效平衡网络负载与能耗,在保证网络服务质量的同时最大化延长网络寿命。

基于虚拟力的水下传感器监控反潜策略研究

近年来无人潜航器对海上重要目标的威胁逐渐增大,体积小、噪声低、行动隐蔽的特点使其很难被发现。为此提出了一个基于虚拟力的传感器监控网络构建算法,通过将三维地形分割,得到面积最小的垂直切面。在该切面上部署传感器,定义了传感器所受重力、互相之间斥力以及边界斥力,在合力的作用下达到平衡状态时完成传感器部署。理论分析和仿真验证表明,提出的算法对复杂地形适应性强,能够根据覆盖率要求得到对应的传感器部署策略,与传统方法相比更灵活,且通过与VFOPCA算法比较,其能耗更低收敛更快。该研究对监控无人潜航器的侵入有指导借鉴意义。

一种能量均衡的水下无线传感器网络覆盖空洞修补方法

针对现有水下无线传感器网络空洞修补方法需要空洞边界探测、通信和计算开销大、覆盖率和能量均衡性差、水下环境模型过于理想化等问题,考虑水底地形复杂,且通常存在较大障碍物等环境因素,建立了基于能量的节点之间、区域边界、零能量空洞、低能量覆盖洞、水底地形及障碍物作用力等多维度的虚拟力模型,提出了基于上述虚拟力模型和能量均衡的空洞修补算法。该算法不需要精确的空洞边界探测,对水下复杂地形和不同环境具有良好的适应性和鲁棒性。此外,提出的对低能量节点、低能量覆盖洞冗余修补的策略,显著提高了修补后网络能量分布的均衡性,减少了因低能量节点的能量很快耗尽而出现新的覆盖空洞的频率,减少了空洞修补频次,降低了网络维护成本。

基于IABC-VFA融合的水下传感网络覆盖优化研究

针对水下无线节点不均匀部署导致的覆盖率低的问题,将改进人工蜂群结合虚拟力算法(Improved Artificial Bee Colony-Virtual Force Algorithm, IABC-VFA)用于水下无线网络覆盖中,改进寻优精度不足以及易陷入局部优化的缺点。首先,在初始阶段引入Tent混沌映射产生混沌序列以获得更均匀的搜索空间;其次,在跟随蜂阶段引入虚拟力算法对雇佣蜂阶段生成的解进行蜜源位置优化更新。最后,引入柯西-高斯变异策略变异当前最优解,使其跳出局部最优。仿真实验对比表明,本文提出的IABC-VFA算法比3D-IVFA和DABVF算法分别提高了1.30%和1.63%的覆盖率,节点利用率优于其他2种算法,可应用于三维水下无线传感器网络节点部署。