Abstract: Wireless sensor networks (WSNs) have gained
tremendous attention in recent years due to their numerous
applications. Due to the limited energy resource, energy efficient
operation of sensor nodes is a key issue in wireless sensor networks.
Cooperative caching which ensures sharing of data among various
nodes reduces the number of communications over the wireless
channels and thus enhances the overall lifetime of a wireless sensor
network. In this paper, we propose a cooperative caching scheme
called ZCS (Zone Cooperation at Sensors) for wireless sensor
networks. In ZCS scheme, one-hop neighbors of a sensor node form a
cooperative cache zone and share the cached data with each other.
Simulation experiments show that the ZCS caching scheme achieves
significant improvements in byte hit ratio and average query latency
in comparison with other caching strategies.
Abstract: This paper describes a 2.4 GHz passive switch mixer
and a 5/2.5 GHz voltage-controlled negative Gm oscillator (VCO)
with an inversion-mode MOS varactor. Both circuits are implemented
using a 1P8M 0.13 μm process. The switch mixer has an input
referred 1 dB compression point of -3.89 dBm and a conversion
gain of -0.96 dB when the local oscillator power is +2.5 dBm.
The VCO consumes only 1.75 mW, while drawing 1.45 mA from a
1.2 V supply voltage. In order to reduce the passives size, the VCO
natural oscillation frequency is 5 GHz. A clocked CMOS divideby-
two circuit is used for frequency division and quadrature phase
generation. The VCO has a -109 dBc/Hz phase noise at 1 MHz
frequency offset and a 2.35-2.5 GHz tuning range (after the frequency
division), thus complying with ZigBee requirements.
Abstract: Like any sentient organism, a smart environment
relies first and foremost on sensory data captured from the real
world. The sensory data come from sensor nodes of different
modalities deployed on different locations forming a Wireless Sensor
Network (WSN). Embedding smart sensors in humans has been a
research challenge due to the limitations imposed by these sensors
from computational capabilities to limited power. In this paper, we
first propose a practical WSN application that will enable blind
people to see what their neighboring partners can see. The challenge
is that the actual mapping between the input images to brain pattern
is too complex and not well understood. We also study the
connectivity problem in 3D/2D wireless sensor networks and propose
distributed efficient algorithms to accomplish the required
connectivity of the system. We provide a new connectivity algorithm
CDCA to connect disconnected parts of a network using cooperative
diversity. Through simulations, we analyze the connectivity gains
and energy savings provided by this novel form of cooperative
diversity in WSNs.
Abstract: Developments in communication technologies
especially in wireless have enabled the progress of low-cost and lowpower
wireless sensor networks (WSNs). The features of such WSN
are holding minimal energy, weak computational capabilities,
wireless communication and an open-medium nature where sensors
are deployed. WSN is underpinned by application driven such as
military applications, the health sector, etc. Due to the intrinsic nature
of the network and application scenario, WSNs are vulnerable to
many attacks externally and internally. In this paper we have focused
on the types of internal attacks of WSNs based on OSI model and
discussed some security requirements, characterizers and challenges
of WSNs, by which to contribute to the WSN-s security research.
Abstract: Wireless Sensor Networks consist of small battery
powered devices with limited energy resources. once deployed, the
small sensor nodes are usually inaccessible to the user, and thus
replacement of the energy source is not feasible. Hence, One of the
most important issues that needs to be enhanced in order to improve
the life span of the network is energy efficiency. to overcome this
demerit many research have been done. The clustering is the one of
the representative approaches. in the clustering, the cluster heads
gather data from nodes and sending them to the base station. In this
paper, we introduce a dynamic clustering algorithm using genetic
algorithm. This algorithm takes different parameters into
consideration to increase the network lifetime. To prove efficiency of
proposed algorithm, we simulated the proposed algorithm compared
with LEACH algorithm using the matlab
Abstract: A model to identify the lifetime of target tracking
wireless sensor network is proposed. The model is a static clusterbased
architecture and aims to provide two factors. First, it is to
increase the lifetime of target tracking wireless sensor network.
Secondly, it is to enable good localization result with low energy
consumption for each sensor in the network. The model consists of
heterogeneous sensors and each sensing member node in a cluster
uses two operation modes–active mode and sleep mode. The
performance results illustrate that the proposed architecture consumes
less energy and increases lifetime than centralized and dynamic
clustering architectures, for target tracking sensor network.
Abstract: We propose an enhanced key management scheme
based on Key Infection, which is lightweight scheme for tiny sensors.
The basic scheme, Key Infection, is perfectly secure against node
capture and eavesdropping if initial communications after node
deployment is secure. If, however, an attacker can eavesdrop on
the initial communications, they can take the session key. We use
common neighbors for each node to generate the session key. Each
node has own secret key and shares it with its neighbor nodes. Then
each node can establish the session key using common neighbors-
secret keys and a random number. Our scheme needs only a few
communications even if it uses neighbor nodes- information. Without
losing the lightness of basic scheme, it improves the resistance against
eavesdropping on the initial communications more than 30%.
Abstract: One of the most important applications of
wireless sensor networks is data collection. This paper
proposes as efficient approach for data collection in wireless
sensor networks by introducing Member Forward List. This list
includes the nodes with highest priority for forwarding the data.
When a node fails or dies, this list is used to select the next node
with higher priority. The benefit of this node is that it prevents
the algorithm from repeating when a node fails or dies. The
results show that Member Forward List decreases power
consumption and latency in wireless sensor networks.
Abstract: Wireless Sensor Networks (WSN) are emerging
because of the developments in wireless communication technology and miniaturization of the hardware. WSN consists of a large number of low-cost, low-power, multifunctional sensor nodes to monitor physical conditions, such as temperature, sound, vibration, pressure,
motion, etc. The MAC protocol to be used in the sensor networks must be energy efficient and this should aim at conserving the energy during its operation. In this paper, with the focus of analyzing the
MAC protocols used in wireless Adhoc networks to WSN, simulation
experiments were conducted in Global Mobile Simulator
(GloMoSim) software. Number of packets sent by regular nodes, and received by sink node in different deployment strategies, total energy
spent, and the network life time have been chosen as the metric for comparison. From the results of simulation, it is evident that the IEEE 802.11 protocol performs better compared to CSMA and MACA protocols.
Abstract: This paper presents an analysis of the localization accuracy of indoor positioning systems using Cramer-s rule via IEEE 802.15.4 wireless sensor networks. The objective is to study the impact of the methods used to convert the received signal strength into the distance that is used to compute the object location in the wireless indoor positioning system. Various methods were tested and the localization accuracy was analyzed. The experimental results show that the method based on the empirical data measured in the non line-of-sight (NLOS) environment yield the highest localization accuracy; with the minimum error distance less than 3 m.
Abstract: To meet the demands of wireless sensor networks
(WSNs) where data are usually aggregated at a single source prior to
transmitting to any distant user, there is a need to establish a tree
structure inside any given event region. In this paper , a novel
technique to create one such tree is proposed .This tree preserves the
energy and maximizes the lifetime of event sources while they are
constantly transmitting for data aggregation. The term Decentralized
Lifetime Maximizing Tree (DLMT) is used to denote this tree.
DLMT features in nodes with higher energy tend to be chosen as data
aggregating parents so that the time to detect the first broken tree link
can be extended and less energy is involved in tree maintenance. By
constructing the tree in such a way, the protocol is able to reduce the
frequency of tree reconstruction, minimize the amount of data loss
,minimize the delay during data collection and preserves the energy.
Abstract: Smart Grids employ wireless sensor networks for
their control and monitoring. Sensors are characterized by limitations
in the processing power, energy supply and memory spaces, which
require a particular attention on the design of routing and data
management algorithms.
Since most routing algorithms for sensor networks, focus on
finding energy efficient paths to prolong the lifetime of sensor
networks, the power of sensors on efficient paths depletes quickly,
and consequently sensor networks become incapable of monitoring
events from some parts of their target areas. In consequence, the
design of routing protocols should consider not only energy
efficiency paths, but also energy efficient algorithms in general.
In this paper we propose an energy efficient routing protocol for
wireless sensor networks without the support of any location
information system. The reliability and the efficiency of this protocol
have been demonstrated by simulation studies where we compare
them to the legacy protocols. Our simulation results show that these
algorithms scale well with network size and density.
Abstract: This paper focuses on reducing the power consumption
of wireless sensor networks. Therefore, a communication protocol
named LEACH (Low-Energy Adaptive Clustering Hierarchy) is modified.
We extend LEACHs stochastic cluster-head selection algorithm
by a modifying the probability of each node to become cluster-head
based on its required energy to transmit to the sink. We present
an efficient energy aware routing algorithm for the wireless sensor
networks. Our contribution consists in rotation selection of clusterheads
considering the remoteness of the nodes to the sink, and then,
the network nodes residual energy. This choice allows a best distribution
of the transmission energy in the network. The cluster-heads
selection algorithm is completely decentralized. Simulation results
show that the energy is significantly reduced compared with the
previous clustering based routing algorithm for the sensor networks.
Abstract: Due to heavy energy constraints in WSNs clustering is
an efficient way to manage the energy in sensors. There are many
methods already proposed in the area of clustering and research is
still going on to make clustering more energy efficient. In our paper
we are proposing a minimum spanning tree based clustering using
divide and conquer approach. The MST based clustering was first
proposed in 1970’s for large databases. Here we are taking divide and
conquer approach and implementing it for wireless sensor networks
with the constraints attached to the sensor networks. This Divide and
conquer approach is implemented in a way that we don’t have to
construct the whole MST before clustering but we just find the edge
which will be the part of the MST to a corresponding graph and
divide the graph in clusters there itself if that edge from the graph can
be removed judging on certain constraints and hence saving lot of
computation.
Abstract: Wireless Sensor Networks (WSNs) have attracted the attention of many researchers. This has resulted in their rapid integration in very different areas such as precision agriculture,environmental monitoring, object and event detection and military surveillance. Due to the current WSN characteristics this technology is specifically useful in industrial areas where security, reliability and autonomy are basic, such as nuclear power plants, chemical plants, and others. In this paper we present a system based on WSNs to monitor environmental conditions around and inside a nuclear power plant, specifically, radiation levels. Sensor nodes, equipped with radiation sensors, are deployed in fixed positions throughout the plant. In addition, plant staff are also equipped with mobile devices with higher capabilities than sensors such as for example PDAs able to monitor radiation levels and other conditions around them. The system enables communication between PDAs, which form a Mobile Ad-hoc Wireless Network (MANET), and allows workers to monitor remote conditions in the plant. It is particularly useful during stoppage periods for inspection or in the event of an accident to prevent risk situations.
Abstract: The major challenge faced by wireless sensor networks is security. Because of dynamic and collaborative nature of sensor networks the connected sensor devices makes the network unusable. To solve this issue, a trust model is required to find malicious, selfish and compromised insiders by evaluating trust worthiness sensors from the network. It supports the decision making processes in wireless sensor networks such as pre key-distribution, cluster head selection, data aggregation, routing and self reconfiguration of sensor nodes. This paper discussed the kinds of trust model, trust metrics used to address attacks by monitoring certain behavior of network. It describes the major design issues and their countermeasures of building trust model. It also discusses existing trust models used in various decision making process of wireless sensor networks.
Abstract: The wireless link can be unreliable in realistic wireless
sensor networks (WSNs). Energy efficient and reliable data
forwarding is important because each node has limited resources.
Therefore, we must suggest an optimal solution that considers using
the information of the node-s characteristics. Previous routing
protocols were unsuited to realistic asymmetric WSNs. In this paper,
we propose a Protocol that considers Both sides of Link-quality and
Energy (PBLE), an optimal routing protocol that balances modified
link-quality, distance and energy. Additionally, we propose a node
scheduling method. PBLE achieves a longer lifetime than previous
routing protocols and is more energy-efficient. PBLE uses energy,
local information and both sides of PRR in a 1-hop distance. We
explain how to send data packets to the destination node using the
node's information. Simulation shows PBLE improves delivery rate
and network lifetime compared to previous schemes. Moreover, we
show the improvement in various WSN environments.
Abstract: During the last couple of years, the degree of dependence on IT systems has reached a dimension nobody imagined to be possible 10 years ago. The increased usage of mobile devices (e.g., smart phones), wireless sensor networks and embedded devices (Internet of Things) are only some examples of the dependency of modern societies on cyber space. At the same time, the complexity of IT applications, e.g., because of the increasing use of cloud computing, is rising continuously. Along with this, the threats to IT security have increased both quantitatively and qualitatively, as recent examples like STUXNET or the supposed cyber attack on Illinois water system are proofing impressively. Once isolated control systems are nowadays often publicly available - a fact that has never been intended by the developers. Threats to IT systems don’t care about areas of responsibility. Especially with regard to Cyber Warfare, IT threats are no longer limited to company or industry boundaries, administrative jurisdictions or state boundaries. One of the important countermeasures is increased cooperation among the participants especially in the field of Cyber Defence. Besides political and legal challenges, there are technical ones as well. A better, at least partially automated exchange of information is essential to (i) enable sophisticated situational awareness and to (ii) counter the attacker in a coordinated way. Therefore, this publication performs an evaluation of state of the art Intrusion Detection Message Exchange protocols in order to guarantee a secure information exchange between different entities.
Abstract: In over deployed sensor networks, one approach
to Conserve energy is to keep only a small subset of sensors
active at Any instant. For the coverage problems, the monitoring
area in a set of points that require sensing, called demand points, and
consider that the node coverage area is a circle of range R, where R
is the sensing range, If the Distance between a demand point and
a sensor node is less than R, the node is able to cover this point. We
consider a wireless sensor network consisting of a set of sensors
deployed randomly. A point in the monitored area is covered if it is
within the sensing range of a sensor. In some applications, when the
network is sufficiently dense, area coverage can be approximated by
guaranteeing point coverage. In this case, all the points of wireless
devices could be used to represent the whole area, and the working
sensors are supposed to cover all the sensors. We also introduce
Hybrid Algorithm and challenges related to coverage in sensor
networks.
Abstract: This paper presents preliminary results regarding system-level power awareness for FPGA implementations in wireless sensor networks. Re-configurability of field programmable gate arrays (FPGA) allows for significant flexibility in its applications to embedded systems. However, high power consumption in FPGA becomes a significant factor in design considerations. We present several ideas and their experimental verifications on how to optimize power consumption at high level of designing process while maintaining the same energy per operation (low-level methods can be used additionally). This paper demonstrates that it is possible to estimate feasible power consumption savings even at the high level of designing process. It is envisaged that our results can be also applied to other embedded systems applications, not limited to FPGA-based.