15,663 research outputs found
Energy efficient geographic routing for wireless sensor networks.
A wireless sensor network consists of a large number of low-power nodes equipped with wireless radio. For two nodes not in mutual transmission range, message exchanges need to be relayed through a series of intermediate nodes, which is a process known as multi-hop routing. The design of efficient routing protocols for dynamic network topologies is a crucial for scalable sensor networks. Geographic routing is a recently developed technique that uses locally available position information of nodes to make packet forwarding decisions. This dissertation develops a framework for energy efficient geographic routing. This framework includes a path pruning strategy by exploiting the channel listening capability, an anchor-based routing protocol using anchors to act as relay nodes between source and destination, a geographic multicast algorithm clustering destinations that can share the same next hop, and a lifetime-aware routing algorithm to prolong the lifetime of wireless sensor networks by considering four important factors: PRR (Packet Reception Rate), forwarding history, progress and remaining energy. This dissertation discusses the system design, theoretic analysis, simulation and testbed implementation involved in the aforementioned framework. It is shown that the proposed design significantly improves the routing efficiency in sensor networks over existing geographic routing protocols. The routing methods developed in this dissertation are also applicable to other location-based wireless networks
Sidewinder: A Predictive Data Forwarding Protocol for Mobile Wireless Sensor Networks
Abstract—In-situ data collection for mobile wireless sensor network deployments has received little study, such as in the case of floating sensor networks for storm surge and innundation monitoring. We demonstrate through quantitative study that traditional approaches to routing in mobile environments do not work well due to volatile topology changes. Consequently, we propose Sidewinder, a predictive data forwarding protocol for mobile wireless sensor networks. Like a heat-seeking missile, data packets are guided towards a sink node with increasing accuracy as packets approach the sink. Different from conventional sensor network routing protocols, Sidewinder continuously predicts the current sink location based on distributed knowledge of sink mobility among nodes in a multi-hop routing process. More-over, the continuous sink estimation is scaled and adjusted to perform with resource-constrained wireless sensors. Our design is implemented with nesC and evaluated in TOSSIM. The per-formance evaluation demonstrates that Sidewinder significantly outperforms state-of-the-art solutions in packet delivery ratio, time delay, and energy efficiency. I
A Review of the Energy Efficient and Secure Multicast Routing Protocols for Mobile Ad hoc Networks
This paper presents a thorough survey of recent work addressing energy
efficient multicast routing protocols and secure multicast routing protocols in
Mobile Ad hoc Networks (MANETs). There are so many issues and solutions which
witness the need of energy management and security in ad hoc wireless networks.
The objective of a multicast routing protocol for MANETs is to support the
propagation of data from a sender to all the receivers of a multicast group
while trying to use the available bandwidth efficiently in the presence of
frequent topology changes. Multicasting can improve the efficiency of the
wireless link when sending multiple copies of messages by exploiting the
inherent broadcast property of wireless transmission. Secure multicast routing
plays a significant role in MANETs. However, offering energy efficient and
secure multicast routing is a difficult and challenging task. In recent years,
various multicast routing protocols have been proposed for MANETs. These
protocols have distinguishing features and use different mechanismsComment: 15 page
From carbon nanotubes and silicate layers to graphene platelets for polymer nanocomposites
In spite of extensive studies conducted on carbon nanotubes and silicate layers for their polymer-based nanocomposites, the rise of graphene now provides a more promising candidate due to its exceptionally high mechanical performance and electrical and thermal conductivities. The present study developed a facile approach to fabricate epoxy–graphene nanocomposites by thermally expanding a commercial product followed by ultrasonication and solution-compounding with epoxy, and investigated their morphologies, mechanical properties, electrical conductivity and thermal mechanical behaviour. Graphene platelets (GnPs) of 3.5
Multihop clustering algorithm for load balancing in wireless sensor networks
The paper presents a new cluster based routing algorithm that exploits the redundancy properties of the sensor networks in order to address the traditional problem of load balancing and energy efficiency in the WSNs.The algorithm makes use of the nodes in a sensor network of which area coverage is covered by the neighbours of the nodes and mark them as temporary cluster heads. The algorithm then forms two layers of multi hop communication. The bottom layer which involves intra cluster communication and the top layer which involves inter cluster communication involving the temporary cluster heads. Performance studies indicate that the proposed algorithm solves effectively the problem of load balancing and is also more efficient in terms of energy consumption from Leach and the enhanced version of Leach
An Outline of Security in Wireless Sensor Networks: Threats, Countermeasures and Implementations
With the expansion of wireless sensor networks (WSNs), the need for securing
the data flow through these networks is increasing. These sensor networks allow
for easy-to-apply and flexible installations which have enabled them to be used
for numerous applications. Due to these properties, they face distinct
information security threats. Security of the data flowing through across
networks provides the researchers with an interesting and intriguing potential
for research. Design of these networks to ensure the protection of data faces
the constraints of limited power and processing resources. We provide the
basics of wireless sensor network security to help the researchers and
engineers in better understanding of this applications field. In this chapter,
we will provide the basics of information security with special emphasis on
WSNs. The chapter will also give an overview of the information security
requirements in these networks. Threats to the security of data in WSNs and
some of their counter measures are also presented
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