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A next-generation network (NGN) is an advanced network that exploits multiple broadband and QoS-enabled transport technologies to provide telecommunication services. The principles and requirements of convergence of wireless sensor networks are likely to deliver all the desired benefits of NGN and should be carefully studied. In this paper, we focus on the power consumption topic, which is a fundamental concern in wireless multimedia sensor networks (WMSNs). Node placement in WMSNs has considerable impact on network lifetime. In this paper, we have investigated and developed a power-efficient node placement scheme (PENPS) in linear WMSNs, which can minimize the average energy consumption per node and maximize the network lifetime. The analysis of PENPS and the comparison of performance with the equal-spaced placement scheme (EPS) show that PENPS scheme can significantly decrease the average energy consumption per node, which can prolong the lifetime of sensor nodes and sensor networks effectively. Copyright © 2010 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper presents a new approach for distributed target detection in wireless sensor networks (WSNs). Contrary to the conventional practice where every sensor uses an identical threshold for decision-making, an unequal and dynamic local sensor threshold selection scheme is proposed. This threshold selection scheme is based on a recently proposed statistical metric for multiple testing problems called the False Discovery Rate (FDR). Assuming a signal attenuation model, where the received signal power decays as the distance from the target increases, various performance indices like the system level probability of detection and the probability of false alarm are studied. Simulation results are provided to demonstrate the effectiveness of this approach. [ABSTRACT FROM AUTHOR]

A wireless sensor network consists of many low-cost, low-power sensor nodes, which can perform sensing, simple computation, and transmission of sensed information. Long distance transmission by sensor nodes is not energy efficient since energy consumption is a superlinear function of the transmission distance. One approach to prolonging network lifetime while preserving network connectivity is to deploy a small number of costly, but more powerful, relay nodes whose main task is communication with other sensor or relay nodes. In this paper, we assume that sensor nodes have communication range r > 0, while relay nodes have communication range R ≥ r, and we study two versions of relay node placement problems. In the first version, we want to deploy the minimum number of relay nodes so that, between each pair of sensor nodes, there is a connecting path consisting of relay and/or sensor nodes. In the second version, we want to deploy the minimum number of relay nodes so that, between each pair of sensor nodes, there is a connecting path consisting solely of relay nodes. We present a polynomial time 7-approximation algorithm for the first problem and a polynomial time (5 + ϵ)-approximation algorithm for the second problem, where ϵ > 0 can be any given constant. [ABSTRACT FROM AUTHOR]

This paper introduces a lightweight architectural solution for discovery, monitoring and management of nodes, services and resources in smart spaces composed of low capacity nodes. A wireless sensor network software architecture is used as the baseline and is extended to a scalable smart space architecture. Discovery, monitoring and management tasks are realized by means of a Resource Manager that acts as just another node. The proposed architecture is deployed on physical wireless sensor nodes. Experimental results show that the proposed smart space architecture is indeed lightweight and suitable for very low capacity nodes. [ABSTRACT FROM AUTHOR]

The article examines a position-based clustering technique for ad hoc intervehicle communication. The paper proposes a new clustering strategy for large multihop vehicular ad hoc networks. It presents the stability of the proposed cluster structure, and communication overhead for maintaining the structure and connectivity in an application context. According to the report, the cluster structure is determined by the geographic position of nodes and the priorities associated with the vehicle traffic information.

Protecting implemented security mechanisms and trusting their output (e.g. log files) when the host, under which they are deployed, is compromised, is among the major challenges that have to be faced. To fulfil this need, recent advances in security have considered the design of storage-based intrusion detection system, which detect intrusions by looking at the low-level disk requests patterns. However, these systems neither tolerate intrusions, nor do they distinguish whether the disk requests are generated by legitimate or malicious processes; and consequently, they generate a lot of false negative and positive alerts. In this paper, we present a Cooperative Intrusion Detection and Tolerance System, called CIDTS, which takes advantage of the information that are available at the network, host operating system, and storage level to better detect intrusion attempts in their early stages, even when the host is compromised. To allow cooperation, the disk communication interface that transports requests between the storage level and the host level is extended to forward information about the processes that generate the request. The paper also provides intrusion tolerance capabilities and provides techniques to support investigation activities. Copyright © 2007 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Contention-based Geographic Forwarding (CGF) is a state-free forwarding technique. In this paper, we develop a general analytical framework to evaluate the performance of CGF with different forwarding areas in wireless multi-hop networks. In particular, we compare the performance of CGF for three typical forwarding areas, analytically and by extensive simulations. We further investigate the impact of several important assumptions on our analytical results. Our study provides guidelines regarding the selection of a specific forwarding area during the design phase of a CGF protocol. It also serves as a general performance evaluation framework for CGF protocols as well as traditional geographic forwarding protocols. [ABSTRACT FROM AUTHOR]

In most of the wireless sensor and actor network applications, it is desirable to have an autonomous process for positioning the actors in order to eliminate human intervention as much as possible. For this purpose, sensors and actors deployed in an area of interest can collaborate in a distributed manner. Typically, sensors can instruct actors for their positioning in the area by considering the application level interests. This instruction is based on selecting representative sensor locations. One of the most common ways of selecting such representative locations is to cluster the network and determine cluster heads (CHs) as representatives. The actors can then move to such CH locations by talking to nearby sensors/actors. Such movement, however, should be done wisely in order to minimise the movement distance of actors so that their lifetimes can be extended. Nevertheless, this may not be possible since not all the actor and CH locations will be known by each actor. In this paper, we propose an actor-CH location matching algorithm which assigns the actors to appropriate CH locations in a distributed manner with minimised travel distance on actors and message overhead on sensors. We adapt the Gale-Shapley (GS) stable matching algorithm from stable matching theory. In this matching algorithm, actors are regarded as men and CHs are regarded as women. For distributed execution of the algorithm, sub-networks of actors and CHs are determined. Each sub-network elects a leader that performs the matching in the sub-network based on GS algorithm. If there are unmatched actors after this process, either a separate search is used to detect such nodes or leaders talk to each other to share this information so that further matching can be performed. We have evaluated the performance of our approach through simulation and shown that our approach can produce travel distance results that are very close to the brute-force approach with minimal messaging overhead. [ABSTRACT FROM AUTHOR]

A precise localization is required in order to maximize the usage of Mobile Sensor Network. As well, mobile robots also need a precise localization mechanism for the same reason. In this paper, we showed a combination of various localization mechanisms for precise localization in three different levels. Localization can be classified in three big categories: wide area and long distance localization with low accuracy, medium area and distance localization with medium accuracy, and small area short distance localization with high accuracy. In order to present localization methods, traditional map building technologies such as grid maps or topological maps can be used. We implemented mobile sensor vehicles and composed mobile sensor network with three levels of localization techniques. Each mobile sensor vehicles act as a mobile sensor node with the facilities such as autonomous driving, obstacle detection and avoidance, map building, communication via wireless network, image processing, extensibility of multiple heterogeneous sensors, and so on. For localization, each mobile sensor vehicle has abilities of the location awareness by mobility trajectory based localization, RSSI based localization and computer vision based localization. With this set of mobile sensor network, we have the possibility to demonstrate various localization mechanisms and their effectiveness. In this paper, the result of computer vision based localization, sensor mobility trail based localization and RSSI based localization will be presented. [ABSTRACT FROM AUTHOR]

Data generated in wireless sensor networks may not all be alike: some data may be more important than others and hence may have different delivery requirements. In this paper, we address differentiated data delivery in the presence of congestion in wireless sensor networks. We propose a class of algorithms that enforce differentiated routing based on the congested areas of a network and data priority. The basic protocol, called Congestion-Aware Routing (CAR), discovers the congested zone of the network that exists between high-priority data sources and the data sink and, using simple forwarding rules, dedicates this portion of the network to forwarding primarily high-priority traffic. Since CAR requires some overhead for establishing the high-priority routing zone, it is unsuitable for highly mobile data sources. To accommodate these, we define MAC-Enhanced CAR (MCAR), which includes MAC-layer enhancements and a protocol for forming high-priority paths on the fly for each burst of data. MCAR effectively handles the mobility of high-priority data sources, at the expense of degrading the performance of low-priority traffic. We present extensive simulation results for CAR and MCAR, and an implementation of MCAR on a 48-node testbed. [ABSTRACT FROM AUTHOR]

Intrusion detection in Wireless Sensor Network (WSN) is of practical interest in many applications such as detecting an intruder in a battlefield. The intrusion detection is defined as a mechanism for a WSN to detect the existence of inappropriate, incorrect, or anomalous moving attackers. For this purpose, it is a fundamental issue to characterize the WSN parameters such as node density and sensing-range in terms of a desirable detection probability. In this paper, we consider this issue according to two WSN models: homogeneous and heterogeneous WSN. Furthermore, we derive the detection probability by considering two sensing models: single-sensing detection and multiple-sensing detection. In addition, we discuss the network connectivity and broadcast reachability, which are necessary conditions to ensure the corresponding detection probability in a WSN. Our simulation results validate the analytical values for both homogeneous and heterogeneous WSNs. [ABSTRACT FROM AUTHOR]

Locationing problem in Wireless Sensor Networks(WSNs) can be viewed as a general distributed sensor problem. It is with sensors that can discover other nodes or estimate ranges between nodes, that serve as position references. In this paper, we show that sensors acquire coarse-grain location awareness by the training protocol. The training protocol which hybrids the synchronization and training procedure. In this protocol, synchronization and training are combined into one scheme. The sink node sends two beacons in each slot instead of one. In the training, sensor searching for its location using a binary search scheme. Our simulation results shown less number of cycles needed for training. [ABSTRACT FROM AUTHOR]

The Internet of Things (IoT) promises widespread connection of sensors and devices such that smart cities, connected transport and other similar visions can be realised. However, to realise this a new wireless technology is required that is optimised for this particular application, providing very low cost, extremely long battery life and excellent coverage. This wireless technology needs to be an open global standard in order to foster a vibrant eco-system of key players. This paper discusses the issues involved in developing standards in the wireless telecommunications space before using a possible new IoT wireless standard as a case study to illustrate the issues with standardisation. [ABSTRACT FROM AUTHOR]

Connected coverage, which reflects how well a target field is monitored under the base station, is the most important performance metric used to measure the quality of surveillance that wireless sensor networks (WSNs) can provide. To facilitate the measurement of this metric, we propose two novel algorithms for individual sensor nodes to identify whether they are on the coverage boundary, i.e., the boundary of a coverage hole or network partition. Our algorithms are based on two novel computational geometric techniques called localized Voronoi and neighbor embracing polygons. Compared to previous work, our algorithms can be applied to WSNs of arbitrary topologies. The algorithms are fully distributed in the sense that only the minimal position information of one-hop neighbors and a limited number of simple local computations are needed, and thus are of high scalability and energy efficiency. We show the correctness and efficiency of our algorithms by theoretical proofs and extensive simulations. [ABSTRACT FROM AUTHOR]

We provide a better sufficient condition for the connectivity of cluster heads asymptotically almost surely (a.a.s.) and a tighter bound on the number of cluster heads in HEED [1]. [ABSTRACT FROM AUTHOR]