引入移动节点的无线传感器网络

文章围绕引入移动节点可以节省无线传感器网络的能量消耗这一主题,对引入了移动节点的无线传感器网络的数据收集方式进行了一个全面合理的分类,并且结合相关文献对每类数据收集方式展开深入讨论,系统全面地论述了该主题的研究现状、存在的问题以及面临的挑战。     

Mobility Management for Hierarchical Wireless Networks

In this paper, we consider the mobility management in large, hierarchically organized multihop wireless networks. The examples of such networks range from battlefield networks, emergency disaster relief and law enforcement etc. We present a novel network addressing architecture to accommodate mobility using a Home Agent concept akin to mobile IP. We distinguish between the physical routing hierarchy (dictated by geographical relationships between nodes) and logical hierarchy of subnets in which the members move as a group (e.g., company, brigade, battalion in the battlefield). The performance of the mobility management scheme is investigated through simulation.     

Handling Mobility in Wireless Sensor and Actor Networks

In Wireless Sensor and Actor Networks (WSANs), the collaborative operation of sensors enables the distributed sensing of a physical phenomenon, while actors collect and process sensor data and perform appropriate actions. WSANs can be thought of as a distributed control system that needs to timely react to sensor information with an effective action. In this paper, coordination and communication problems in WSANs with mobile actors are studied. First, a new location management scheme is proposed to handle the mobility of actors with minimal energy expenditure for the sensors, based on a hybrid strategy that includes location updating and location prediction. Actors broadcast location updates limiting their scope based on Voronoi diagrams, while sensors predict the movement of actors based on Kalman filtering of previously received updates. The location management scheme enables efficient geographical routing, and based on this, an optimal energy-aware forwarding rule is derived for sensor-actor communication. Consequently, algorithms are proposed that allow controlling the delay of the data-delivery process based on power control, and deal with network congestion by forcing multiple actors to be recipients for traffic generated in the event area. Finally, a model is proposed to optimally assign tasks to actors and control their motion in a coordinated way to accomplish the tasks based on the characteristics of the events. Performance evaluation shows the effectiveness of the proposed solution.     

Exploiting Mobility for Efficient Coverage in Sparse Wireless Sensor Networks

Reliable monitoring of a large area with a Wireless Sensor Network (WSN) typically requires a very large number of stationary nodes, implying a prohibitive cost and excessive (radio) interference. Our objective is to develop an efficient system that will employ a smaller number of stationary nodes that will collaborate with a small set of mobile nodes in order to improve the area coverage. The main strength of this collaborative architecture stems from the ability of the mobile sensors to sample areas not covered (monitored) by stationary sensors. An important element of the proposed system is the ability of each mobile node to autonomously decide its path based on local information (i.e. a combination of self collected measurements and information gathered by stationary sensors in the mobile’s communication range), which is essential in the context of large, distributed WSNs. The contribution of the paper is the development of a simple distributed algorithm that allows mobile nodes to autonomously navigate through the field and improve the area coverage. We present simulation results based on a real sparse stationary WSN deployment for the coverage improvement scenario.     

Terminal-Controlled Mobility Management in Heterogeneous Wireless Networks

The coexistence of multiple access technologies deployed by different operators is fundamental for future fourth-generation mobile networks. In spite of this heterogeneity, seamless interoperator/intersystem mobility is a mandatory requirement. In this article we present a seamless mobility management approach that does not require changes to existing network infrastructure. The novelty of the proposed approach is that mobility management is fully controlled by the terminal, and network selection is user-centric, power-saving, cost-aware, and performance-aware. Total mobility management, including interface management, handover decision, and execution, is also detailed     

UMTS全IP无线网络的移动性管理

文章讨论了3GPP UMTS全IP无线网络中的两种运行模式:传输模式和本机模式,3个不同层次移动性支持:接入移动性、宽域移动性和微移动性.对基于路由和基于隧道两种移动性管理协议进行了比较,并介绍了基于多协议标志交换(MPLS)的分级移动性管理方案,该方案利用标志边界移动性代理的增强MPLS路由器,使网络具有灵活性、可升级性和无隙缝移动性.     

Deploying Wireless Sensor Networks under Limited Mobility Constraints

In this paper, we study the issue of sensor network deployment using limited mobility sensors. By limited mobility, we mean that the maximum distance that sensors are capable of moving to is limited. Given an initial deployment of limited mobility sensors in a field clustered into multiple regions, our deployment problem is to determine a movement plan for the sensors to minimize the variance in number of sensors among the regions and simultaneously minimize the sensor movements. Our methodology to solve this problem is to transfer the nonlinear variance/movement minimization problem into a linear optimization problem through appropriate weight assignments to regions. In this methodology, the regions are assigned weights corresponding to the number of sensors needed. During sensor movements across regions, larger weight regions are given higher priority compared to smaller weight regions, while simultaneously ensuring a minimum number of sensor movements. Following the above methodology, we propose a set of algorithms to our deployment problem. Our first algorithm is the optimal maximum flow-based (OMF) centralized algorithm. Here, the optimal movement plan for sensors is obtained based on determining the minimum cost maximum weighted flow to the regions in the network. We then propose the simple peak-pit-based distributed (SPP) algorithm that uses local requests and responses for sensor movements. Using extensive simulations, we demonstrate the effectiveness of our algorithms from the perspective of variance minimization, number of sensor movements, and messaging overhead under different initial deployment scenarios.     

Mobile IP-Based Protocol for Wireless Personal Area Networks in Critical Environments

Low-power Wireless Personal Area Networks (LoWPANs) are still in their early stage of development, but the range of conceivable usage scenarios and applications is tremendous. That range is extended by its inclusion in Internet with IPv6 Low-Power Personal Area Networks (6LoWPANs). This makes it obvious that multi-technology topologies, security and mobility support will be prevalent in 6LoWPAN. Mobility based communication increases the connectivity, and allows extending and adapting LoWPANs to changes in their location and environment infrastructure. However, the required mobility is heavily dependent on the individual service scenario and the LoWPAN architecture. In this context, an optimized solution is proposed for critical applications, such as military, fire rescue or healthcare, where people need to frequently change their position. Our scenario is health monitoring in an oil refinery where many obstacles have been found to the effective use of LoWPANs in these scenarios, mainly due to transmission medium features i.e. high losses, high latency and low reliability. Therefore, it is very difficult to provide continuous health monitoring with such stringent requirements on mobility. In this paper, a paradigm is proposed for mobility over 6LoWPAN for critical environments. On the one hand the intra-mobility is supported by GinMAC, which is an extension of IEEE 802.15.4 to support a topology control algorithm, which offers intra-mobility transparently, and Movement Direction Determination (MDD) of the Mobile Node (MN). On the other hand, the inter-mobility is based on pre-set-up of the network parameters in the visited networks, such as Care of Address and channel, to reach a fast and smooth handoff. Pre-set-up is reached since MDD allows discovering the next 6LoWPAN network towards which MN is moving. The proposed approach has been simulated, prototyped, evaluated, and is being studied in a scenario of wearable physiological monitoring in hazardous industrial areas, specifically oil refineries, in the scope of the GinSeng European project.     

Sensing Coverage for Wireless Sensor Networks in Shadowed Rician Fading Environments

Wireless Personal Communications - The effect of shadowing and multipath fading on sensing coverage has been studied in this paper. Rician fading is one of the most widely occurring type of...     

Exploiting Mobility for Energy Efficient Data Collection in Wireless Sensor Networks

We analyze an architecture based on mobility to address the problem of energy efficient data collection in a sensor network. Our approach exploits mobile nodes present in the sensor field as forwarding agents. As a mobile node moves in close proximity to sensors, data is transferred to the mobile node for later depositing at the destination. We present an analytical model to understand the key performance metrics such as data transfer, latency to the destination, and power. Parameters for our model include: sensor buffer size, data generation rate, radio characteristics, and mobility patterns of mobile nodes. Through simulation we verify our model and show that our approach can provide substantial savings in energy as compared to the traditional ad-hoc network approach. Sushant Jain is a Ph.D. candidate in the Department of Computer Science and Engineering at the University of Washington. His research interests are in design and analysis of routing algorithms for networking systems. He received a MS in Computer Science from the University of Washington in 2001 and a B.Tech degree in Computer Science from IIT Delhi in 1999. Rahul C. Shah completed the B. Tech (Hons) degree from the Indian Institute of Technology, Kharagpur in 1999 majoring in Electronics and Electrical Communication Engineering. He is currently pursuing his Ph.D. in Electrical Engineering at the University of California, Berkeley. His research interests are in energy-efficient protocol design for wireless sensor/ad hoc networks, design methodology for protocols and next generation cellular networks. Waylon Brunette is a Research Engineer in the Department of Computer Science and Engineering at the University of Washington. His research interests include mobile and ubiquitous computing, wireless sensor networks, and personal area networks. Currently, he is engaged in collaborative work with Intel Research Seattle to develop new uses for embedded devices and RFID technologies in ubiquitous computing. He received a BS in Computer Engineering from the University of Washington in 2002. Gaetano Borriello is a Professor in the Department of Computer Science and Engineering at the University of Washington. His research interests are in embedded and ubiquitous computing, principally new hardware devices that integrate seamlessly into the user’s environment with particular focus on location and identification systems. His principal projects are in creating manageable RFID systems that are sensitive to user privacy concerns and in context-awareness through sensors distributed in the environment as well as carried by users. Sumit Roy received the B. Tech. degree from the Indian Institute of Technology (Kanpur) in 1983, and the M. S. and Ph. D. degrees from the University of California (Santa Barbara), all in Electrical Engineering in 1985 and 1988 respectively, as well as an M. A. in Statistics and Applied Probability in 1988. His previous academic appointments were at the Moore School of Electrical Engineering, University of Pennsylvania, and at the University of Texas, San Antonio. He is presently Prof, of Electrical Engineering, Univ. of Washington where his research interests center around analysis/design of communication systems/networks, with a topical emphasis on next generation mobile/wireless networks. He is currently on academic leave at Intel Wireless Technology Lab working on high speed UWB radios and next generation Wireless LANs. His activities for the IEEE Communications Society includes membership of several technical committees and TPC for conferences, and he serves as an Editor for the IEEE Transactions on Wireless Communications.     

Exploiting Reactive Mobility for Collaborative Target Detection in Wireless Sensor Networks

Recent years have witnessed the deployments of wireless sensor networks in a class of mission-critical applications such as object detection and tracking. These applications often impose stringent Quality-of-Service requirements including high detection probability, low false alarm rate, and bounded detection delay. Although a dense all-static network may initially meet these Quality-of-Service requirements, it does not adapt to unpredictable dynamics in network conditions (e.g., coverage holes caused by death of nodes) or physical environments (e.g., changed spatial distribution of events). This paper exploits reactive mobility to improve the target detection performance of wireless sensor networks. In our approach, mobile sensors collaborate with static sensors and move reactively to achieve the required detection performance. Specifically, mobile sensors initially remain stationary and are directed to move toward a possible target only when a detection consensus is reached by a group of sensors. The accuracy of final detection result is then improved as the measurements of mobile sensors have higher Signal-to-Noise Ratios after the movement. We develop a sensor movement scheduling algorithm that achieves near-optimal system detection performance under a given detection delay bound. The effectiveness of our approach is validated by extensive simulations using the real data traces collected by 23 sensor nodes.     

Policy Based Mobility &; Flow Management for IPv6 Heterogeneous Wireless Networks

We propose a dynamic mobility management framework for Internet Protocol version 6 (IPv6) and policy enforcement enabled heterogenous wireless networks. Policies and policy rules are defined depending on network infrastructure facilities, service agreements and negotiation results. Each traffic is coupled with an identifiable traffic flow while the heterogenous interface flow bindings are regulated by polices. The network selection, flow distribution, handovers and mobility procedures are flexible and we propose to improve the decision making via Multiple Attributes Decision Making (MADM). Techniques considered in the framework include the IPv6 based Network Mobility (NEMO), multihoming capability, transparent vertical handovers, horizontal handovers and dynamic policy enforcement matching process to improve the Quality of Service (QoS), Quality of Experience (QoE) and ubiquitous connectivity. A experiment testbed and simulation models have been constructed to verify the mobility framework performance in a heterogeneous WiFi, WiMax and UMTS hybrid environment.     

Distributed Mobility Management for Target Tracking in Mobile Sensor Networks

Mobility management is a major challenge in mobile ad hoc networks (MANETs) due in part to the dynamically changing network topologies. For mobile sensor networks that are deployed for surveillance applications, it is important to use a mobility management scheme that can empower nodes to make better decisions regarding their positions such that strategic tasks such as target tracking can benefit from node movement. In this paper, we describe a distributed mobility management scheme for mobile sensor networks. The proposed scheme considers node movement decisions as part of a distributed optimization problem which integrates mobility-enhanced improvement in the quality of target tracking data with the associated negative consequences of increased energy consumption due to locomotion, potential loss of network connectivity, and loss of sensing coverage.     

An Intra-PAN Mobility Management Scheme for IPv6 over Low-Power Wireless Personal Area Networks

This paper proposes an intra-PAN mobility management scheme for IPv6 over Low-power wireless personal area networks （6LoWPAN） on the basis of ＂networkbased＂ idea. We developed a tree-like network architecture which includes coordinate nodes for packet routing. All of the control messages are designed to transmit in link layer, and the sensor nodes are free to consider care-of address and the mobile nodes are unnecessary to deal with any mobility handoff messages. The simulation results show that this scheme efficiently cuts down the signaling cost and reduces the energy consumed by fixed nodes which can extend the life time of the whole Personal area networks （PAN）.     

适用于传感器网络的分级群组密钥管理

 由于无线传感器网络中经常出现节点加入或离开网络的情况,所以需要建立一种安全高效的群组密钥管理系统来保证无线传感器网络中群组通信的安全性.提出了一种基于密钥树和中国剩余定理的分级群组密钥管理方案.有sensor节点加入,先向新成员发送二级群组密钥,可参与一些不太敏感的数据的传送;待新成员获得GCKS的信任之后,则向其发送群组密钥,从而可参与有关机密信息的会话.节点离开时,通过利用完全子集方法将剩余成员进行分割,提出的方案可以利用中国剩余定理对群组密钥进行安全的更新.证明方案满足正确性、群组密钥保密性、前向保密性和后向保密性等安全性质.性能分析表明,此方案适合应用于无线传感器网络环境.     

Hierarchical Architecture for Multi-Technology Wireless Sensor Networks for Critical Infrastructure Protection

A hierarchical architecture for wireless sensor network (WSN) consisting of heterogeneous devices is introduced in this paper. Proposed architecture is well suited for surveillance of critical infrastructures and it is designed to be scalable for various different scenarios. Low power consumption will be achieved by utilizing a wake-up radio concept which enables to keep the most power consuming devices at the sleep mode as long as possible. A WSN OpenAPI gateway (WOAG) component of the architecture supports high scalability by enabling data collection and sharing from networks deployed using multiple different technologies. WOAG facilitates WSNs information availability to local and remote end-users. Analytical energy efficiency optimization model for the architecture is developed. Results show energy efficiency gains that can be achieved with the proposed wake-up concept based intelligent hierarchical architecture design. For low event frequency case the energy efficiency is found to be one order of magnitude better than for duty cycle (1 %) radio based network.     

Mobility Prediction Based Tracking of Moving Objects in Wireless Sensor Networks

This paper investigates the multi-sensor fused localization of moving targets in a wireless sensor network. Each ultra-wide band(UWB) sensor is assigned a stability weight according to its survival time prediction. The measurement accuracy of each sensor into the constraints of the weight distribution based on the interactive multi-model method, a double weight distribution algorithm that considers measurement accuracy and stability is proposed. Based on the double weight algorithm,the measureme...     

Fuzzy Rule-Based Mobility and Load Management for Self-Organizing Wireless Networks

Mobility management in a cluster-based, multihop ad hoc network is studied. It is shown that the process of clustering the network into groups of stations has similarities to data analysis, in particular, pattern recognition. In data analysis, the term clustering refers to the process of unsupervised learning, which also describes the situation in a mobile ad hoc network.In this paper, existing data-clustering algorithms are first classified into different categories. Some of the most important types of algorithms are afterwards described, and their applicability to the problem of mobility management in an ad hoc network is studied. It is shown that most of the pattern-recognition algorithms are not suited to the application under consideration.This is why we have developed a new clustering scheme that incorporates some of the ideas of the data classification schemes. The new clustering scheme is based on a rule-based fuzzy inference engine. The main idea consists of the consideration of dynamic clustering events chosen as a consequence of the fuzzy rules. Four types of clustering events are considered.The performance of the clustering algorithm has been evaluated by computer simulation.