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Abstract: In many applications of wireless sensor networks, sensor nodes are manually deployed in hostile environments where an attacker can disrupt the localization service and tamper with legitimate in-network communication. In this article, we introduce Secure Walking GPS, a practical and cost effective secure localization and key distribution solution for real, manual deployments of WSNs. Using the location information provided by the GPS and inertial guidance modules on a special master node, Secure Walking GPS achieves accurate node localization and location-based key distribution at the same time. We evaluate our localization solution in real deployments of MicaZ. Our experiments show that 100% of the deployed nodes localize (i.e., have a location position) and that the average localization errors are within 1–2m, due mainly to the limitations of the existing commercial GPS devices. Our further analysis and simulation results indicate that the Secure Walking GPS scheme makes a deployed WSN resistant to the Dolev-Yao, the wormhole, and the GPS-denial attacks, the scheme is practical for large-scale deployments with resource-constrained sensor nodes and has good localization and key distribution performance. [Copyright &y& Elsevier]

Body sensor networks (BSNs) are emerging cyber–physical systems that promise to improve quality of life through improved healthcare, augmented sensing and actuation for the disabled, independent living for the elderly, and reduced healthcare costs. However, the physical nature of BSNs introduces new challenges. The human body is a highly dynamic physical environment that creates constantly changing demands on sensing, actuation, and quality of service (QoS). Movement between indoor and outdoor environments and physical movements constantly change the wireless channel characteristics. These dynamic application contexts can also have a dramatic impact on data and resource prioritization. Thus, BSNs must simultaneously deal with rapid changes to both top–down application requirements and bottom–up resource availability. This is made all the more challenging by the wearable nature of BSN devices, which necessitates a vanishingly small size and, therefore, extremely limited hardware resources and power budget. Current research is being performed to develop new principles and techniques for adaptive operation in highly dynamic physical environments, using miniaturized, energy-constrained devices. This paper describes a holistic cross-layer approach that addresses all aspects of the system, from low-level hardware design to higher level communication and data fusion algorithms, to top-level applications. [ABSTRACT FROM PUBLISHER]

Energy efficiency is a fundamental issue for outdoor sensor network systems. This article presents the design and implementation of multidimensional power management strategies in VigilNet, a major recent effort to support long-term surveillance using power-constrained sensor devices. A novel tripwire service is integrated with an effective sentry and duty cycle scheduling in order to increase the system lifetime, collaboratively. The tripwire service partitions a network into distinct, nonoverlapping sections and allows each section to be scheduled independently. Sentry scheduling selects a subset of nodes, the sentries, which are turned on while the remaining nodes save energy. Duty cycle scheduling allows the active sentries themselves to be turned on and off, further lowering the average power draw. The multidimensional power management strategies proposed in this article were fully implemented within a real sensor network system using the XSM platform. We evaluate key system parameters using a network of 200 XSM nodes in an outdoor environment, and an analytical probabilistic model.We evaluate network lifetime using a simulation of a 10,000-node network that uses measured XSM power values. These evaluations demonstrate the effectiveness of our integrated approach and identify a set of lessons and guidelines, useful for the future development of energy-efficient sensor systems. One of the key results indicates that the combination of the three presented power management techniques is able to increase the lifetime of a realistic network from 4 days to 200 days. [ABSTRACT FROM AUTHOR]

The article discusses the hardware and software that go into creating wireless sensor networks (WSNs). Topics include the hardware characteristics of smart wireless sensor devices, wireless communications stacks, sensing stacks, middleware services, the operating system, and software application. WSNs have current and potential applications in energy, medicine, military applications, and agriculture. WSNs can be attached to the Internet, and future developments may see WSN data available via Internet search engines.

The article reports on the study conducted by Radu Stoleru of Texas A&M University and John A. Stankovic and Sang H. Son of the University of Virginia on node localization in wireless sensor networks and the potential of localization protocol composability in the U.S. There are several wireless sensor network (WSN) systems are developed for several domains including military surveillance, environmental monitoring, habitat monitoring and structural monitoring. When researchers studied how one can effectively locate sensor nodes at low cost, they failed because despite the myriads of schemes available in the market, no robust localization system has potential to provide the solution needed. Presented are the details of the research.

The article focuses on opportunities and obligations for physical computing systems. Seamlessly integrating computing with the physical world via sensors and actuators, physical computing systems promise to give society an improved living standard, greater security, and unparalleled convenience and efficiency. To better understand physical computing's advantages, this article gives emphasis on three application areas. These include assisted living, emergency response systems for natural or man-made disasters, and protecting critical infrastructures at the national level.

In this paper, we present a spatiotemporal communication protocol for sensor networks, called SPEED. SPEED is specially tailored to be a localized algorithm with minimal control overhead. End-to-end soft real-time communication is achieved by maintaining a desired delivery speed across the sensor network through a novel combination of feedback control and nondeterministic geographic forwarding. SPEED is a highly efficient and scalable protocol for sensor networks where the resources of each node are scarce. Theoretical analysis, simulation experiments, and a real implementation on Berkeley motes are provide to validate the claims. [ABSTRACT FROM AUTHOR]