Secure aggregation in hybrid mesh/sensor networks

The advantages of deploying mobile sinks (MSs) in wireless sensor networks (WSNs) have attracted tremendous attention recently, because mobility of a sink provides an efficient method to improve data gathering performance in WSNs. However, in such kind of WSN, the efficiency of data dissemination is obviously affected by the trajectory of the MS. Therefore, optimal moving schemes of the MS have been studied in many researches. Nevertheless, in many cases, the trajectory of the MS is not able to change ideally as previous studies assumed but depending on the environmental conditions. In this paper, we focus on the efficiency of data gathering in WSN with a MS whose trajectory cannot change ideally and propose a new data diffusion scheme - implementing a new Pre-Diffusion Algorithm (PDA) in a hierarchical WSN aimed at improving data gathering efficiency. This hierarchical WSN is composed of several clusters, and datatransmission is done by higher powered cluster head (CH) node. Our scheme predetermines the cluster area where the MS is going to arrive in most probability in next period of time. MS fulfills data converging in the cluster head (CH)whose distance to the MS may the smallest compared with other CHs when data gathering starts. Thus more data can be collected with less trajectory length of MS. Simulation results show that our proposed scheme improves data gathering efficiency as compared to conventional scheme.

Wireless Sensor Networks (WSNs) are a class of technology represented with a set of sensor nodes. The main objective of these nodes is to collect data and monitor an environment's events. The basic tasks a node can handle are sensing data (humidity, temperature, fire, etc.), transmitting over short distances, and performing limited data processing. Common WSNs are used in many application fields. The limited resources of the WSNs (low processing capacity, memory and energy reserves) makes them underexploited compared to the WSNs' spectrum utilization. Therefore their applications can be significantly increased by enhancing their performance. To address this challenge, cognitive radio sensor networks (CRSNs) examine how wireless sensor nodes with cognitive radio capabilities can address these performance challenges and improve the spectrum utilization. A new kind of WSN (CRSN) with better performance is created throgh the introduction of cognitive radio to traditional sensor networks. This new class of WSNS is more adapted to some specific applications which require more resources capabilities. In this talk, I will offer a perspective on the emerging field of cognitive radio sensor networks and its current applications.

Many applications for agricultural information and environment monitoring exploit buried sensors wired-connected to the soil surface for information retrieval.A novel wireless underground sensor networks is a specialized kind of wireless sensor network that communicates through soil.The wireless underground sensor networks (WUSN) consist of wireless devices that are buried completely under dense soil and operate below the ground surface.In this paper, the application research of the wireless underground sensor networks is described.Experimental measurements of the signal strength and packet error rate are presented at the frequency of 433MHz, which show a good agreement with the theoretical studies.The results show the buried depth of the WUSN node and the volumetric water content of the soil are the most important factor to adversely affect the communication.

Based on the principles of wireless mesh network (WMN), clustering of wireless sensor network (WSN) was reconstructed by combination of WMN and WSN into a topology named wireless mesh sensor network (WMSN). In terms of Voronoi diagram and Delaunay triangulations of computational geometry, central degree theory of complex network and heuristic algorithm based on mean weight of communication energy, a optimal deployment algorithm named WHD algorithm which can figure out large scale WMSN was designed. The study results show that the combination of WSN and WMN can achieve mesh wide hybrid network topology; WHD algorithm can be an effective solution to optimal deployment of large-scale WMSN. The experimental results show that WHD algorithm not only ensures optimal deployment of large-scale WMSN but also has the energy saved features, and then extends the network life-cycle efficiently.

Infrastructure monitoring is an important class of wireless sensor network (WSN) applications. When the topology of a WSN designed for infrastructure monitoring is linear in nature, such as bridges, highways and pipelines, this kind of WSN is known to be linear WSN (LWSN). To achieve the high-reliable infrastructure monitoring services, hybrid LWSN has been designed where a limited number of support nodes are used to transfer information. In this work, a multi-valued decision diagram (MDD)-based analytical approach is proposed to evaluate the probability that the hybrid LWSN performs at a particular performance state characterized in terms of the number of sensor nodes being able to reach the base station node. Particularly, novel procedures are proposed to construct MDD models and the complexity of MDD model is investigated. A case study is presented to substantiate the application of the proposed MDD approach.

This paper introduces a new IEEE standard, IEEE 802.15.5,which provides mesh capability for wireless personal area network (WPAN) devices. The standard provides an architectural framework enabling WPAN devices to promote interoperable, stable, and scalable wireless mesh topologies. It is composed of two parts: low-rate WPAN mesh and high-rate WPAN mesh. In this paper, we present only low-rate WPAN mesh because it is designed to support wireless sensor networks. IEEE 802.15.5 low-rate part is a light-weight scalable mesh routing protocol that caters well to the requirements of resource-constrained wireless sensor networks. By binding logical addresses to the network topology, IEEE 802.15.5 obviates the need for route discovery. This eliminates the initial route discovery latency, saves storage space and reduces the communication overhead and energy consumption. A distributed link state scheme is further built atop the block addressing scheme to improve the quality of routes, robustness, and load balancing. The routing scheme scales well with regard to various performance metrics. The standard also provides enhanced functions such as multicast, reliable broadcast, power saving, time synchronization, route tracing and portability. We also present the performance evaluation of major functions performed with a 50-nodes tested deployed over a whole floor (100 × 140 ft2) at CUNY Engineering building. The results testify that the IEEE 802.15.5 will serve well for wireless personal area networks and wireless sensor networks.

UWASN (UnderWater Acoustic Sensor Network) is a kind of WSN (Wireless Sensor Network) consisting of underwater acoustic sensor nodes, which can be deployed for real-time warship monitoring, oceanographic data collection, environmental monitoring, disaster prevention, etc. The design of a reliable data transfer protocol for UWASN is challenging [1] owing to the specific characteristics of acoustic channels: high error rates, high energy consumption, limited bandwidth, low transmission speed, and long and unstable packet delivery delay.

An intelligent community intrusion detection system based on wireless sensor network and fuzzy neural network (FNN) is presented in this paper. This system is composed of ARM (Advanced RISC Machines) data acquisition nodes, wireless mesh network and control centre. The data acquisition node uses sensors to collect information and processes them by image detection algorithm, and then transmits information to control centre with wireless mesh network. When there is abnormal phenomenon, the system starts the camera and the FNN is used to recognize the face image. We construct the structure of fuzzy neural network, and adopt the Levenberg-Marquart optimizing algorithm to train fuzzy neural network, thereby enhancing the convergence rate and the recognition accuracy. With the ability of strong self-learning and nonlinear function approach of fuzzy neural network, the recognition method can truly classify the face. This system resolves the defect and improves the intelligence and alleviates worker's working stress.

A wireless heterogeneous sensor networks (WHSNs) is a kind of wireless sensor networks (WSNs), each sensor may have different sensing units. Sensing nodes can simultaneously monitor different attributes, such as various temperature, brightness, humidity, and so on. MUQC use the changes in number of sensing units and sensing units to adjust the probability of on mode and off mode. After several rounds, the operational number of sensors to achieve the desired number of targets. The result showed that MUQC can effectively schedule the activity of each sensing unit on each sensor to completely cover the targets of interest and turn on the sensing attributes of the sensors in the appropriate round.

Due to the energy limit of sensor nodes, prolonging lifetime of wireless sensor networks (WSNs) is a big challenge. This challenge becomes even more critical in large-scale sensor networks, in which more energy is consumed because of more data collections and packet transmissions. It is believed that clustering-based protocols are the best choice for such kind of WSNs. In this paper, we propose a clustering protocol called fan-shaped clustering (FSC) to partition a large-scale network into fan-shaped clusters. Based on this clustering scheme, different energy saving methods are proposed, such as efficient cluster head and relay selection, locality of re-clustering, simple but robust routing and hotspot solution. Performance analysis demonstrates that the proposed FSC can efficiently save energy, which is much better than hybrid, energy-efficient, and distributed clustering in terms of both energy saving and packet collection rate.

Wireless mesh networks (WMNs) have emerged as a scalable, reliable, and agile wireless network that supports many types of innovative technologies such as the Internet of Things (IoT), Wireless Sensor Networks (WSN), and Internet of Vehicles (IoV). Due to the limited number of orthogonal channels, interference between channels adversely affects the fair distribution of bandwidth among mesh clients, causing node starvation in terms of insufficient bandwidth distribution, which impedes the adoption of WMN as an efficient access technology. Therefore, a fair channel assignment is crucial for the mesh clients to utilize the available resources. However, the node starvation problem due to unfair channel distribution has been vastly overlooked during channel assignment by the extant research. Instead, existing channel assignment algorithms equally distribute the interference reduction on the links to achieve fairness which neither guarantees a fair distribution of the network bandwidth nor eliminates node starvation. In addition, the metaheuristic-based solutions such as genetic algorithm, which is commonly used for WMN, use randomness in creating initial population and selecting the new generation usually leading the search to local minima. To this end, this study proposes a Fairness-Oriented Semichaotic Genetic Algorithm-Based Channel Assignment Technique (FA-SCGA-CAA) to solve node starvation problem in wireless mesh networks. FA-SCGA-CAA maximizes link fairness while minimizing link interference using a genetic algorithm (GA) with a novel nonlinear fairness-oriented fitness function. The primary chromosome with powerful genes is created based on multicriterion links ranking channel assignment algorithm. Such a chromosome was used with a proposed semichaotic technique to create a strong population that directs the search towards the global minima effectively and efficiently. The proposed semichaotic technique was also used during the mutation and parent selection of the new genes. Extensive experiments were conducted to evaluate the proposed algorithm. A comparison with related work shows that the proposed FA-SCGA-CAA reduced the potential node starvation by 22% and improved network capacity utilization by 23%. It can be concluded that the proposed FA-SCGA-CAA is reliable to maintain high node-level fairness while maximizing the utilization of the network resources, which is the ultimate goal of many wireless networks.

CENTRALIZED CONTROL OF WIRELESS SENSOR NETWORKS FOR REAL-TIME APPLICATIONS

Various communication services have been provided. They include environmental monitoring and/or control, ad-hoc communication between mobile nodes, and inter-vehicle communication in intelligent transport systems. As a means of facilitating the above advanced communication services, autonomous decentralized networks, such as wireless sensor networks (Akyildiz et al., 2002; Rajagopalan & Varshney, 2006), mobile ad-hoc networks (Perkins & Royer, 1999; Johnson et al., 2003; Clausen & Jaquet, 2003; Ogier et al., 2003), and wireless mesh networks (Yamamoto et al., 2009), have been intensively researched with great interests. Especially, a wireless sensor network, which is a key network to construct ubiquitous information environments, has great potential as a means of realizing a wide range of applications, such as natural environmental monitoring, environmental control in residential spaces or plants, object tracking, and precision agriculture (Akyildiz et al., 2002). Recently, there is growing expectation for a new network service by a wireless sensor network consisting of a lot of static sensor nodes arranged in a service area and a few mobile robots as a result of the strong desire for the development of advanced systems that can flexibly function in dynamically changing environments (Matsumoto et al., 2009). In this chapter, a large scale and dense wireless sensor network made up of many static sensor nodes with global positioning system, which is a representative network to actualize the above-mentioned sensor applications, is assumed. In a large scale and dense wireless sensor network, generally, hundreds or thousands of static sensor nodes limited resources, which are compact and inexpensive, are placed in a service area, and sensing data of each node is gathered to a sink node by inter-node wireless multi-hop communication. Each sensor node consists of a sensing function to measure the status (temperature, humidity, motion, etc.) of an observation point or object, a limited function of information processing, and a simplified wireless communication function, and it generally operates on a resource with a limited power-supply capacity such as a battery. Therefore, a data gathering scheme and/or a routing protocol capable of meeting the following requirements is mainly needed to prolong the lifetime of a large scale and dense wireless sensor network composed of hundreds or thousands of static sensor nodes limited resources. 1. Efficiency of data gathering 2. Balance of communication load among sensor nodes 3. Adaptability to network topology changes

Presents a 100-slide tutorial on wireless multihop networks. Wireless mesh networks, mobile ad-hoc networks and wireless sensor networks are some of the names related to a more general concept that can be described as wireless multihop networks. Recently, the research community has devoted a lot of attention to this topic since now it may become applied in a general manner leaving the niche market it has had since its origins. Sometimes, the research community is overoptimistic about the application of this technology, and in fact, in the technology itself. This enthusiasm brings to unrealistic research scenarios and, so, to unrealistic models and conclusions. The topic of the tutorial is motivated for this feeling of lack of connection between reality and theory in the study of this kind of networks. The main ideas presented are based on practical experiences in using this technology and in some well known papers that cover the same issues. The tutorial starts with an introduction to some applications and the technologies available. From this point, different key aspects such as mobility, range, interference, metrics, routing or power consumption are presented considering different degrees of complexity and realism. The tutorial presents measurements from real systems (e.g. WLAN mesh networks and wireless sensor networks) related to range, packet losses, reconfiguration times and the effects of mobility. The tutorial is intended to focus the research in the area, avoiding too general scenarios that provide no clear solutions and to provide some reference behaviors and values to validate simulation or theoretical results.

For its self-organizing, self-configuring, and self-healing capabilities, as well as their low cost and ease of maintenance, Wireless Mesh Networks (WMNs) have emerged as a potential technology for a wide range of applications.  Due to their inherent characteristics such as shared wireless medium, multi-hop and inter-network communication, highly dynamic network topology, and decentralised architecture, securing WMNs is a  more challenging and complex issue.  The WMNs are vulnerable to a variety of MAC layer attacks because of these vulnerabilities. Existing MAC layer standards and implementations are insufficient to secure these functionalities, and they do not provide comprehensive security solutions to protect both the backbone and the client mesh. As a result, efficient, scalable, and integrated security solutions for WMNs are required. We classify MAC layer attacks and examine existing countermeasures in this paper. Based on the classification of attacks and the analysis of countermeasures, we derive research directions for improving the MAC layer security of WMNs.