BiSNET: A biologically-inspired middleware architecture for self-managing wireless sensor networks

This paper describes BiSNET (Biologically-inspired architecture for Sensor NETworks), a middleware architecture that addresses several key issues in multi-modal wireless sensor networks (MWSNs) such as autonomy, scalability, adaptability, self-healing and simplicity. Based on the observation that various biological systems have developed mechanisms to overcome these issues, BiSNET follows certain biological principles such as decentralization, food gathering/storage and natural selection to design MWSN applications. In BiSNET, each application consists of multiple software agents, which operate on the BiSNET middleware platform in individual sensor nodes, and each agent exploits certain biologically-inspired mechanisms such as energy exchange, pheromone emission, replication, migration and death. This is analogous to a bee colony (application) consisting of multiple bees (agents). This paper describes the biologically-inspired mechanisms in BiSNET, and evaluates their impacts on the autonomy, scalability, adaptability, self-healing and simplicity of MWSNs. Simulation results show that BiSNET allows sensor nodes (agents and platforms) to be scalable with respect to network size, autonomously adapt their sleep periods for power efficiency and responsiveness of data collection, adaptively aggregate data from different types of sensor nodes, and collectively self-heal (i.e., detect and eliminate) false positive sensor data. The BiSNET platform is implemented simple in its design and lightweight in its memory footprint.     

Cellular automaton-based algorithms for the dispersion of mobile wireless sensor networks

Due to the advent of sensor technology and its applications, mobile wireless sensor networks (MWSNs) have gained a significant amount of research interest. In a typical MWSN, sensors can move within the network. We develop a set of probabilistic and deterministic cellular automaton (CA)-based algorithms for motion planning problems in MWSNs. First, we consider a scenario where a group of sensors are deployed and they need to disperse in order to maximise the area covered by the network. In this variant of the problem we do not explicitly consider that the sensors should maintain the connectivity of the network while they move. Second, we consider a scenario where the sensors are initially randomly distributed and they need to disperse autonomously to both maximise the coverage of the network and maintain its connectivity. We carry out extensive simulations of both deterministic and randomised variants of the algorithms. For the first variant of the problem we compare our algorithms with one previous algorithm and find that our algorithm yields better network coverage than the earlier algorithm. We also find that probabilistic algorithms have better overall performance for the second variant. CA algorithms rely only on local information about the network and, hence, they can be used in practice for MWSN problems. On the other hand, locality of the algorithm implies that maintaining connectivity becomes a non-trivial problem.     

TURIR：一种能量高效的移动无线传感器网络兴趣消息更新协议＊）

无线传感器网络是近年来兴起的一项新兴技术,在医疗、环境、交通、军事等领域都有重要的应用.随着研究的不断深入,移动无线传感器网络也受到了越来越多的关注.本文研究了移动无线传感器网络中特有的兴趣消息更新问题,提出了基于触发更新、延迟响应与抑制响应和增量更新的兴趣消息更新协议(TURIR).TURIR采用触发更新的方式使兴趣消息更新与节点的移动路径相适应,避免了盲目的定时更新,降低了更新频率;延迟响应与响应抑制避免了消息交换过程中的广播风暴问题.并减少了消息交换的数量;增量更新消除了更新过程中的冗余消息,减少了更新过程中节点间交换的数据量.降低了对网络带宽的需求.理论分析与实验数据均表明.TURIR协议降低了兴趣消息更新的频率,减少了更新过程中的报文数量以及通信数据量,从而降低了无线传感器网络的能量消耗,提高了网络生命周期,适合在移动无线传感器网络中部署.     

基于斯坦纳树和泰森多边形的连通恢复算法

针对无线传感器网络容易遭受恶劣环境破坏,连通恢复后各关键节点的能量损耗远大于其他节点从而导致网络断连的问题,提出基于斯坦纳树和泰森多边形的连通恢复算法（CRAST）。首先,将被分割的节点分区抽象为离散点,枚举出离散点区域内的所有非退化四边形,再使用四边形斯坦纳树结构对这些非退化四边形部署中继节点以达到连通恢复。然后,用关键节点构建Delaunay三角网,通过Delaunay三角网构建出整个无线传感器网络的泰森多边形拓扑结构。最后,在泰森多边形所有顶点部署可移动的备用中继节点,在关键节点损坏时通过比较备用节点所占关键节点对应的所有备用节点比重选择要移动的备用节点,移动备用中继节点替换损坏的关键节点。整个算法能使传感器网络以最少的代价实现连通恢复,并且拥有较强的高效性和健壮性。     

Connectivity and coverage maintenance in wireless sensor networks

One of the main design challenges for wireless sensor networks (WSNs) is to obtain long system lifetime without sacrificing system original performance such as communication connectivity and sensing coverage. A large number of sensor nodes are deployed in redundant fashion in dense sensor networks, which lead to higher energy consumption. We propose a distributed framework for energy efficient connectivity and coverage maintenance in WSNs. In our framework, each sensor makes self-scheduling to separately control the states of RF and sensing unit based on dynamic coordinated reconstruction mechanism. A novel energy-balanced distributed connected dominating set algorithm is presented to make connectivity maintenance; and also a distributed node sensing scheduling is brought forward to maintain the network coverage according to the surveillance requirements. We implemented our framework by C++ programming, and the simulation results show that our framework outperforms several related work by considerably improving the energy performance of sensor networks to effectively extend network lifetime.     

An enhanced real-time routing protocol with load distribution for mobile wireless sensor networks

Mobile wireless sensor network (MWSN) is a wireless ad hoc network that consists of a very large number of tiny sensor nodes communicating with each other in which sensor nodes are either equipped with motors for active mobility or attached to mobile objects for passive mobility. A real-time routing protocol for MWSN is an exciting area of research because messages in the network are delivered according to their end-to-end deadlines (packet lifetime) while sensor nodes are mobile. This paper proposes an enhanced real-time with load distribution (ERTLD) routing protocol for MWSN which is based on our previous routing protocol RTLD. ERTLD utilized corona mechanism and optimal forwarding metrics to forward the data packet in MWSN. It computes the optimal forwarding node based on RSSI, remaining battery level of sensor nodes and packet delay over one-hop. ERTLD ensures high packet delivery ratio and experiences minimum end-to-end delay in WSN and MWSN compared to baseline routing protocol. In this paper we consider a highly dynamic wireless sensor network system in which the sensor nodes and the base station (sink) are mobile. ERTLD has been successfully studied and verified through simulation experiment.     

Mobility-assisted minimum connected cover in a wireless sensor network

All properties of mobile wireless sensor networks (MWSNs) are inherited from static wireless sensor networks (WSNs) and meanwhile have their own uniqueness and node mobility. Sensor nodes in these networks monitor different regions of an area of interest and collectively present a global overview of monitored activities. Since failure of a sensor node leads to loss of connectivity, it may cause a partitioning of the network. Adding mobility to WSNs can significantly increase the capability of the WSN by making it resilient to failures, reactive to events, and able to support disparate missions with a common set of sensor nodes. In this paper, we propose a new algorithm based on the divide-and-conquer approach, in which the whole region is divided into sub-regions and in each sub-region the minimum connected sensor cover set is selected through energy-aware selection method. Also, we propose a new technique for mobility assisted minimum connected sensor cover considering the network energy. We provide performance metrics to analyze the performance of our approach and the simulation results clearly indicate the benefits of our new approach in terms of energy consumption, communication complexity, and number of active nodes over existing algorithms.     

物联网中移动Sensor节点漫游的组合安全认证协议

物联网包含感知子网和传输骨干网,其感知子网中节点能力受限,往往利用移动的传感器节点跨区域访问来获取信息;而其传输骨干网络需要依托现有Internet的基础设施,并利用其提供的强大服务.在这种情况下,移动节点的漫游带来了新的安全问题,一方面移动节点在感知子网间跨区域漫游,虽和MANET中一样需要保证移动节点漫游时高效安全地加入新的拜访域,但因传感节点资源极端受限而对轻量级有更高数量级的要求;另一方面资源受限的感知子网间移动节点漫游仅能提供轻量级安全,但是在接入骨干传输网时,不可因此降低骨干网络已有的安全性,即轻量级的安全协议和传统骨干网协议综合运用时,需具有组合安全性.本文针对这种基于骨干传输网的移动节点漫游问题,提出了一个新的随机漫游认证协议(RMRAP),兼顾安全性和实际应用的可行性,实现了漫游的轻量级身份认证,保护了漫游节点的隐私,同时实现了具有前向安全性,会话密钥对;并针对衔接骨干网和感知子网的基站进行了组合安全性的认证测试,验证了RMRAP的安全性;最后,从理论分析和实验仿真两个方面,分析了RMRAP协议的性能,并和相近工作进行了对比,对比表明,具有组合安全性的RMRAP在计算、通信开销方面,依然具有和同类协议可比较的相近性能.     

移动传感器网络及其路由协议研究进展*

针对移动传感器网络的路由协议可分为两种情况：支持单个或者少数sink节点移动的协议和支持所有节点移动的协议。对每类协议的特点和比较典型的协议进行了介绍,在实际应用中要根据具体的应用情况来设计和选择相应的协议。     

无线传感网络中能量均衡的连通支配集算法

连通支配集是无线传感器网络中构建虚拟骨干网络的重要手段.由于支配集中节点的能耗相对其他节点要多,支配集中剩余能量较小的节点决定了虚拟骨干网的生命周期.现有算法或者只是关注构造较小的支配集,或者没有考虑调整能耗极快的支配节点.提出了一种能量均衡的连通支配集算法,基于节点剩余能量和连通度构造支配集,在网络运行过程中根据耗能速度,提前选择候选支配节点,分流负载过重的支配节点.仿真结果表明,新算法能以较小消息开销,有效延长网络寿命.     

Grid quorum‐based spatial coverage in mobile wireless sensor networks using nature‐inspired firefly algorithm

Optimization and design of mobile wireless sensor networks (MWSNs) must assure adequate spatial coverage of the site. The spatial coverage optimization aims to enrich discoverability of MWSN by specifying mobile sensors geographical locations in order to maximize their coverage. In this paper, an enhanced metaheuristic algorithm called “firefly algorithm with crossover and detection phases” is introduced for optimizing the area coverage percentage of MWSN. The proposed algorithm is tested on many datasets with different criterions and compared with other algorithms including differential evolution, whale optimization algorithm, and flower pollination algorithm. The experimental results are analysed with one‐way ANOVA test. In addition, the proposed algorithm is compared with particle swarm optimization, and the results are analysed with Wilcoxon signed‐rank test. The overall analysis results prove the prosperity and efficient exploration of the proposed algorithm.     

An Adaptive Partitioning Scheme for Sleep Scheduling and Topology Control in Wireless Sensor Networks

This paper presents an adaptive partitioning scheme of sensor networks for node scheduling and topology control with the aim of reducing energy consumption. Our scheme partitions sensors into groups such that a connected backbone network can be maintained by keeping only one arbitrary node from each group in active status while putting others to sleep. Unlike previous approaches that partition nodes geographically, our scheme is based on the measured connectivity between pairwise nodes and does not depend on nodes' locations. In this paper, we formulate node scheduling with topology control as a constrained optimal graph partition problem, which is NP-hard, and propose a Connectivity-based Partition Approach (CPA), which is a distributed heuristic algorithm, to approximate a good solution. We also propose a probability-based CPA algorithm to further save energy. CPA can ensure K-vertex connectivity of the backbone network, which achieves the trade-off between saving energy and preserving network quality. Moreover, simulation results show that CPA outperforms other approaches in complex environments where the ideal radio propagation model does not hold.     

Impact of sensor nodes scaling and velocity on handover mechanisms for healthcare wireless sensor networks with mobility support

Health promotion in hospital environments can be improved using the most recent information and communication technologies. The Internet connectivity to small sensor nodes carried by patients allows remote access to their bio-signals. To promote these features the healthcare wireless sensor networks (HWSN) are used. In these networks mobility support is a key issue in order to keep patients under real-time monitoring even when they move around. To keep sensors connected to the network, they should change their access points of attachment when patients move to a new coverage area along an infirmary. This process, called handover, is responsible for continuous network connectivity to the sensors. This paper presents a detailed performance evaluation study considering three handover mechanisms for healthcare scenarios (Hand4MAC, RSSI-based, and Backbone-based). The study was performed by simulation using several scenarios with different number of sensors and different moving velocities of sensor nodes. The results show that Hand4MAC is the best solution to guarantee almost continuous connectivity to sensor nodes with less energy consumption.     

Formation of a geometric pattern with a mobile wireless sensor network

Mobile wireless sensor networks (MWSNs) will enable information systems to gather detailed information about the environment on an unprecedented scale. These self‐organizing, distributed networks of sensors, processors, and actuators that are capable of movement have a broad range of potential applications, including military reconnaissance, surveillance, planetary exploration, and geophysical mapping. In many of the foreseen applications, the MWSN will need to form a geometric pattern without assistance from the user. In military reconnaissance, for example, the nodes will be dropped onto the battlefield from a plane and land at random positions. The nodes will be expected to arrange themselves into a predetermined formation in order to perform a specific task. Thus, we present algorithms for forming a line, circle, and regular polygon from a given set of random positions. The algorithms are distributed and use no communication between the nodes to minimize energy consumption. Unlike past studies of geometric problems where algorithms are either tested in simulations where each node has global knowledge of all the other nodes or implemented on a small number of robots, the robustness of our algorithms has been studied with simulations that model the sensor system in detail. The simulations demonstrate that the algorithms are robust against random errors in the sensors and actuators. © 2004 Wiley Periodicals, Inc.     

无线传感器网络中一种改进的能效数据收集协议

基于连通支配集的虚拟骨干是减少支配节点数量和限制路由搜索空间的关键技术,对于优化无线传感器网络生命起到重要作用。ViTAMin协议不但能通过关闭一些非必要节点产生虚拟骨干,而且能将采集的数据沿着距离基站能耗最低的路径进行发送,以节省能量。针对ViTAMin可能会产生非连通网络且支配节点能耗不均衡的问题,提出了一种基于虚拟骨干的能效数据收集协议EEVB。理论分析证明,EEVB能够以O(n)的时间与信息复杂度构造连通支配集,仿真实验进一步证实EEVB能够以较小的能耗开销构建规模较小的连通支配集,并有效延长网络的生命时间。     

基于可连Cell的无线传感器网络拓扑控制算法

在无线传感器网络的拓扑控制(TC)中,基于Cell的TC算法被认为是一类可以节省传感器节点能量并延长网络生命周期的方法,但是其需要较多的骨干网节点并且无法保证连通性.通过分析现今算法的内在局限性,提出了一种1-Con思想:当一个Cell的头节点被加入当前骨干网时,所有其可以连接的Cell使用该节点连入拓扑结构,然后此新骨干网递归地继续扩大.基于此思想,设计了一种基于可连Cell的拓扑控制算(CCTC),并从理论上证明:1)CCTC可以保证其所形成的拓扑结构维持网络连通;2)每一轮用于形成骨干网的工作节点非常少.CCTC的计算复杂度是线性的,空间复杂度和信息交换量都是常数量级.仿真实验同样显示,CCTC可以在提供良好鲁棒性和较少的消息交换的情况下,更有效地节省节点能耗并延长网络生命周期.     

Energy-efficient bootstrapping for wireless sensor networks

Wireless sensor networks are poised for increasingly wider uses in many military and civil applications. Such applications has stimulated research in a number of research areas related to energy conservation in such networks. Most such research focuses on energy saving in tasks after the network has been organized. Very little attention has been paid to network bootstrapping as a possible phase where energy can be saved. Bootstrapping is the phase in which the entities in a network are made aware of the presence of all or some of the other entities in the network. This paper describes a bootstrapping protocol for a class of sensor networks consisting of a mix of low-energy sensor nodes and a small number of high-energy entities called gateways. We propose a new approach, namely the slotted sensor bootstrapping (SSB) protocol, which focuses on avoiding collisions in the bootstrapping phase and emphasizes turning off node radio circuits whenever possible to save energy. Our mechanism synchronizes the sensor nodes to the gateway’s clock so that time-based communication can be used. The proposed SSB protocol tackles the issue of node coverage in scenarios, when physical device limitations and security precautions prevent some sensor nodes from communicating with the gateways. Additionally, we present an extension of the bootstrapping protocol, which leverages possible gateway mobility.     

C3: an energy-efficient protocol for coverage,connectivity and communication in WSNs

The lower layer of ubiquitous and pervasive systems consists of wireless ad hoc and sensor networks. In wireless sensor networks (WSNs), sensors consume most of their energy in data transmission and idle listening. Hence, efficient usage of energy can be ensured by improved protocols for topology control (i.e., coverage and connectivity), sleep scheduling, communication, and aggregation and compression of data. Though several protocols have been proposed for this purpose, they are not energy-efficient. We propose an integrated and energy-efficient protocol for Coverage, Connectivity, and Communication (C3) in WSNs. The C3 protocol uses received signal strength indicator to divide the network into virtual rings, defines clusters with clusterheads more probably at alternating rings, defines dings that are rings inside a cluster and uses triangular tessellation to identify redundant nodes, and communicates data to sink through clusterheads and gateways. The proposed protocol strives for near-optimal deployment, load balancing, and energy-efficient communication. Simulation results show that the C3 protocol ensures partial coverage of more than 90 % of the total deployment area, ensures one connected network, and facilitates energy-efficient communication while expending only one-fourth of the energy compared to other related protocols such as the coverage and connectivity protocol, and the layered diffusion-based coverage control.     

SA-MAC: Self-Stabilizing Adaptive MAC Protocol for Wireless Sensor Networks

A common method of prolonging the lifetime of wireless sensor networks is to use low power duty cycling protocol. Existing protocols consist of two categories: sender-initiated and receiver-initiated. In this paper, we present SAMAC, a self-stabilizing adaptive MAC protocol for wireless sensor networks. SA-MAC dynamically adjusts the transmission time-slot, waking up time-slot, and packet detection pattern according to current network working condition, such as packet length and wake-up patterns of neighboring nodes. In the long run, every sensor node will find its own transmission phase so that the network will enter a stable stage when the network load and qualities are static. We conduct extensive experiments to evaluate the energy consumption, packet reception rate of SA-MAC in real sensor networking systems. Our results indicate that SA-MAC outperforms other existing protocols.     

基于事件驱动保持网络连通性的WSNs路由协议

为保证无线传感器网络（ WSNs）的连通性,延长网络有效工作期,提出了一种事件驱动成簇、能量高效均衡的路由协议。该协议避免了与事件无关的节点参与成簇而消耗能量,通过簇首选举的控制消息延时转发节省了网络能量,建立了综合考虑当前节点剩余能量和包含其邻居节点的平均剩余能量、当前节点到邻居节点和Sink节点距离的中继路由法则。仿真结果表明：与采用预成簇的AEEC协议和事件驱动成簇的ARPEES协议相比,所提出的路由协议推迟了首个死亡节点的出现时间,使WSNs有效工作期分别提高了4.3倍和47%。