Popularity of ubiquitous computing increases the importance of location-aware applications,
which increases the need for finding location of the user. In this paper, we present a novel localization method
for indoor environments using Wi-Fi infrastructure.
While localization using Wi-Fi is cost effective, handling the obstructions which are the main cause of
signal propagation error in indoor environments is a challenging task. We address this problem in two levels,
resulting in increased accuracy of localization. In the first level, we "localize" the residing area of user node in
coarse granularity. Then, we use building layout to find the objects that attenuate the signal between the
reference node and the coarse estimate of the location of user node. Using multi-wall propagation model, we
apply corrections for all obstructions and find the location of user node. Empirical results based on experiments
conducted in lab-scale, shows meter-level accuracy.
A Fuzzy Based Priority Approach in Mobile Sensor Network CoverageIDES Editor
In this paper a new fuzzy based approach for
improving network coverage in wireless mobile sensor
networks is proposed. In the proposed approach firstly
each mobile sensor node determines its neighbors and its
distance from borders and obstacles. According to these
values, fuzzy inference engine calculates the priority of
node for movement. Then according to the priority, in
turn, nodes move away from each other to increase
coverage area in the target field. Simulation results show
that our fuzzy approach can reach higher degree of
coverage against other common approaches like FOA,
VEC and TRI algorithms.
Communication by Whispers Paradigm for Short Range Communication in Cognitive...IDES Editor
With ever increasing demand for efficiency
and increased throughput over the wireless domain, we
have now reached a point where in a method for efficient
utilization of the electromagnetic spectrum is in demand.
Cognitive radio provides us with a way in which this demand
could be catered, it does so by using devices which
autonomously adjust their communication parameters to
adapt to the external environment. However, the most
critical of this entire technology is the parameter relating to
the Spectrum Sensing aspects. In order for cognitive radio
devices to properly configure and identify the presence of
a primary carrier in a communication mode, spectrum
sensors and efficient sensing algorithms are required. There
have been many algo- rithms developed in this field.
However, these available spectrum sensing algorithms are
prohibitively expensive to implement in wireless devices that
cater to only short distance communication. In this paper,
we propose a parsimonious spectrum sensing algorithm
which would deal with sensing and couple them with short
distance wireless devices over WiFi networks operating in the
2.4 GHz band. The efficiency parameters are also shown
using demonstrations.
Indoor Localization Using Local Node Density In Ad Hoc WSNsjoaquin_gonzalez
Presentation for Master Thesis "Indoor Localization Using Local Node Density In Ad Hoc WSNs", research supported by Free University Berlin. Coordinators: Freddy Lopez Villafuerte, Gianluca Cornetta.
Performance Analysis of V-Blast MIMO System Using Minimum Mean Square Error E...ijtsrd
The V-BLAST MIMO-system some of linear detection techniques can be used for interference cancellation (IC). In this paper, using Minimum Mean Square Error- interference cancellation for the same. In this paper, we analysis of BER performance of Vertical Bell Labs Layered Space Time Architecture (V-BLAST) spatial Multiplexing Technique with equalisation techniques like Minimum Mean Square Error (MMSE) by BPSK modulation techniques in Rayleigh flat fading channel. Tamashri Sonartiya | Deepak Pancholi"Performance Analysis of V-Blast MIMO System Using Minimum Mean Square Error Equalizer Technique with BPSK" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-5 , August 2018, URL: http://www.ijtsrd.com/papers/ijtsrd15804.pdf http://www.ijtsrd.com/engineering/electronics-and-communication-engineering/15804/performance-analysis-of-v-blast-mimo-system-using-minimum-mean-square-error-equalizer-technique-with-bpsk/tamashri-sonartiya
A Fuzzy Based Priority Approach in Mobile Sensor Network CoverageIDES Editor
In this paper a new fuzzy based approach for
improving network coverage in wireless mobile sensor
networks is proposed. In the proposed approach firstly
each mobile sensor node determines its neighbors and its
distance from borders and obstacles. According to these
values, fuzzy inference engine calculates the priority of
node for movement. Then according to the priority, in
turn, nodes move away from each other to increase
coverage area in the target field. Simulation results show
that our fuzzy approach can reach higher degree of
coverage against other common approaches like FOA,
VEC and TRI algorithms.
Communication by Whispers Paradigm for Short Range Communication in Cognitive...IDES Editor
With ever increasing demand for efficiency
and increased throughput over the wireless domain, we
have now reached a point where in a method for efficient
utilization of the electromagnetic spectrum is in demand.
Cognitive radio provides us with a way in which this demand
could be catered, it does so by using devices which
autonomously adjust their communication parameters to
adapt to the external environment. However, the most
critical of this entire technology is the parameter relating to
the Spectrum Sensing aspects. In order for cognitive radio
devices to properly configure and identify the presence of
a primary carrier in a communication mode, spectrum
sensors and efficient sensing algorithms are required. There
have been many algo- rithms developed in this field.
However, these available spectrum sensing algorithms are
prohibitively expensive to implement in wireless devices that
cater to only short distance communication. In this paper,
we propose a parsimonious spectrum sensing algorithm
which would deal with sensing and couple them with short
distance wireless devices over WiFi networks operating in the
2.4 GHz band. The efficiency parameters are also shown
using demonstrations.
Indoor Localization Using Local Node Density In Ad Hoc WSNsjoaquin_gonzalez
Presentation for Master Thesis "Indoor Localization Using Local Node Density In Ad Hoc WSNs", research supported by Free University Berlin. Coordinators: Freddy Lopez Villafuerte, Gianluca Cornetta.
Performance Analysis of V-Blast MIMO System Using Minimum Mean Square Error E...ijtsrd
The V-BLAST MIMO-system some of linear detection techniques can be used for interference cancellation (IC). In this paper, using Minimum Mean Square Error- interference cancellation for the same. In this paper, we analysis of BER performance of Vertical Bell Labs Layered Space Time Architecture (V-BLAST) spatial Multiplexing Technique with equalisation techniques like Minimum Mean Square Error (MMSE) by BPSK modulation techniques in Rayleigh flat fading channel. Tamashri Sonartiya | Deepak Pancholi"Performance Analysis of V-Blast MIMO System Using Minimum Mean Square Error Equalizer Technique with BPSK" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-5 , August 2018, URL: http://www.ijtsrd.com/papers/ijtsrd15804.pdf http://www.ijtsrd.com/engineering/electronics-and-communication-engineering/15804/performance-analysis-of-v-blast-mimo-system-using-minimum-mean-square-error-equalizer-technique-with-bpsk/tamashri-sonartiya
Single User Eigenvalue Based Detection For Spectrum Sensing In Cognitive Rad...IJMER
Scarcity of spectrum is the issue that wireless communication technology has to deal with.
Primary user is the licensed user of the spectrum. When primary user is idle or not using the spectrum
secondary user can utilize the spectrum. This sharing of spectrum can be enabled by cognitive radio
(CR) technology. The heart of enabling this technology is spectrum sensing. Spectrum sensing involves
detection of primary signal at very low SNR (in the range of -20 dB), under noise and interference
uncertainty. This requirement makes spectrum sensing, a hard nut to crack. Another major issue in
detection is hidden node problem wherein the node in vicinity of primary transmitter also indicates
absence of the primary signal since it is hidden behind the large object. There are various algorithms
for detection viz. energy detection, matched filter detection, feature detection (cyclostationary
detection, eigen-value based detection etc.) These algorithms have limitations of complexity,
requirement of signal knowledge and detection performance. In this paper the performance of
eigenvalue based detection (EBD) method in presence of noise and low SNR of the received signal has
been evaluated for a single user.
IOSR Journal of Electronics and Communication Engineering(IOSR-JECE) is an open access international journal that provides rapid publication (within a month) of articles in all areas of electronics and communication engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electronics and communication engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
TARGET LOCALIZATION IN WIRELESS SENSOR NETWORKS BASED ON RECEIVED SIGNAL STRE...sipij
We consider the problem of localizing a target taking the help of a set of anchor beacon nodes. A small
number of beacon nodes are deployed at known locations in the area. The target can detect a beacon
provided it happens to lie within the beacon’s transmission range. Thus, the target obtains a measurement
vector containing the readings of the beacons: ‘1’ corresponding to a beacon if it is able to detect the
target, and ‘0’ if the beacon is not able to detect the target. The goal is twofold: to determine the location
of the target based on the binary measurement vector at the target; and to study the behaviour of the
localization uncertainty as a function of the beacon transmission range (sensing radius) and the number of
beacons deployed. Beacon transmission range means signal strength of the beacon to transmit and receive
the signals which is called as Received Signal Strength (RSS). To localize the target, we propose a gridmapping
based approach, where the readings corresponding to locations on a grid overlaid on the region
of interest are used to localize the target. To study the behaviour of the localization uncertainty as a
function of the sensing radius and number of beacons, extensive simulations and numerical experiments
are carried out. The results provide insights into the importance of optimally setting the sensing radius and
the improvement obtainable with increasing number of beacons.
MULTI-STAGES CO-OPERATIVE/NONCOOPERATIVE SCHEMES OF SPECTRUM SENSING FOR COGN...ijwmn
Searching for spectrum holes in practical wireless channels where primary users experience multipath
fading and shadowing, with noise uncertainty, limits the detection performance significantly. Moreover, the
detection challenge will be tougher when different band types have to be sensed, with different signal and
spectral characteristics, and probably overlapping spectra. Besides, primary user waveforms can be known
(completely or partially) or unknown to allow or forbid cognitive radios to use specific kinds of detection
schemes! Hidden primary user’s problem, and doubly selective channel oblige the use of cooperative
sensing to exploit the spatial diversity in the observations of spatially located cognitive radio users.
Incorporated all the aforementioned practical challenges as a whole, this paper developed a new multistage detection scheme that intelligently decides the detection algorithm based on power, noise, bandwidth
and knowledge of the signal of interest. The proposed scheme switches between individual and cooperative
sensing and among featured based sensing techniques (cyclo-stationary detection and matched filter) and
sub-band energy detection according to the characteristics of signal and band of interest.Compared to the
existing schemes, performance evaluations show reliable results in terms of probabilities of detection and
mean sensing times under the aforementioned conditions.
Effective range free localization scheme for wireless sensor networkijmnct
Location aware sensors can be used in many areas such as military and civilian applications. Wireless
Sensor Networks help to identify the accurate location of the event. In this paper a cost effective schema for
localization has been proposed. It uses two beacon nodes to identify the location of unknown nodes. It
also uses flooding and estimating method to accurately identify the location of other nodes. Available area
is divided into zones and beacons are provided for each zone. Beacon nodes are placed in appropriate
locations normally two in a zone to provide location information. Using the two nodes location of unknown
nodes can be calculated accurately.
Simulation of Direct Sequence Spread Spectrum for Wireless Communication Syst...ijtsrd
In this work, a simulation model for Direct Sequence Spread Spectrum (DSSS) scheme for wireless communication systems has been proposed. Unlike the case of a single frequency carrier, the modulated signal in DSSS occupies a much wider bandwidth in order to reduce the possible interferences with narrow band communication signals. In telecommunications, DSSS is a spread spectrum modulation technique used to reduce overall signal interference. The spreading of this signal makes the resulting wideband channel more noisy, allowing for greater resistance to unintentional and intentional interference. Y.V.S Durga Prasad | K. Venkateswarlu"Simulation of Direct Sequence Spread Spectrum for Wireless Communication Systems using Simulink" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-4 , June 2018, URL: http://www.ijtsrd.com/papers/ijtsrd14118.pdf http://www.ijtsrd.com/engineering/electronics-and-communication-engineering/14118/simulation-of-direct-sequence-spread-spectrum-for-wireless-communication-systems-using-simulink/yvs-durga-prasad
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
PARTICLE FILTER APPROACH TO UTILIZATION OF WIRELESS SIGNAL STRENGTH FOR MOBIL...ijwmn
For many autonomous robotic applications, the capability to simultaneously create a map of the environment while localizing its position within it is of critical importance. This is typically achieved by fusing odometry information from the robotic vehicle with information from landmarks detected within the
environment. Indoor environments often have existing wireless infrastructure, which can be used as landmarks by estimating the distance between the robot and the access point. The most practical way to attain this is by measuring the decay of signal strength. However, radio signal strength does not predictably attenuate indoors as it does in open environments due to signal interference, absorption, and reflection from objects within the environment, inflicting unexpected amplification or decay at the receiver known as multipath interference. This causes erroneous distance estimations due to the unexpected changes
in signal strength attenuation. In this research, models of radio propagation as it relates to the received signal strength indicator (RSSI) are explored along with localization techniques which utilize these models. For development and testing of RSSI-based localization techniques, a simulation method has been
described which utilizes a Markov chain to provide realistic multipath interference on simulated RSSI data. Using this simulation technique, methods for simultaneous localization and mapping (SLAM) are explored. Due to the difficulty associated with modeling RSSI attenuation and distance estimation, a particle filter based SLAM approach is proposed and demonstrated.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
The peer-reviewed International Journal of Engineering Inventions (IJEI) is started with a mission to encourage contribution to research in Science and Technology. Encourage and motivate researchers in challenging areas of Sciences and Technology.
Supercapacitors or EDLCs (i.e. electric double-layer capacitors) or ultra-capacitors are becoming increasingly popular as alternatives for the conventional and traditional battery sources. This brief overview focuses on the different types of supercapacitors, the relevant quantitative modeling areas and the future of supercapacitor research and development. Supercapacitors may emerge as the solution for many application-specific power systems. Especially, there has been great interest in developing supercapacitors for electric vehicle hybrid power systems, pulse power applications, as well as back-up and emergency power supplies. Because of their flexibility, however, supercapacitors can be adapted to serve in roles for which electrochemical batteries are not as well suited. Also, supercapacitors have some intrinsic characteristics that make them ideally suited to specialized roles and applications that complement the strengths of batteries. In particular, supercapacitors have great potential for applications that require a combination of high power, short charging time, high cycling stability and long shelf life. So, let’s just begin the innovative journey of these near future of life-long batteries that can charge up almost anything and everything within a few seconds!
Vehicle routing problem is a NP-hard problem, with the expansion of problem solving more difficult.
This paper proposes a hybrid behavior based on ant colony algorithm to solve the problem, ant to different
objectives in the first place as the path selection according to the analysis of the impact on the algorithm, then
define the ant behavior and design four concrete ant behavior by selecting different ways of ant behavior to
form different improved algorithm. Finally, experimental results show that the improved algorithm can solve
vehicle routing problems quickly and effectively.
Single User Eigenvalue Based Detection For Spectrum Sensing In Cognitive Rad...IJMER
Scarcity of spectrum is the issue that wireless communication technology has to deal with.
Primary user is the licensed user of the spectrum. When primary user is idle or not using the spectrum
secondary user can utilize the spectrum. This sharing of spectrum can be enabled by cognitive radio
(CR) technology. The heart of enabling this technology is spectrum sensing. Spectrum sensing involves
detection of primary signal at very low SNR (in the range of -20 dB), under noise and interference
uncertainty. This requirement makes spectrum sensing, a hard nut to crack. Another major issue in
detection is hidden node problem wherein the node in vicinity of primary transmitter also indicates
absence of the primary signal since it is hidden behind the large object. There are various algorithms
for detection viz. energy detection, matched filter detection, feature detection (cyclostationary
detection, eigen-value based detection etc.) These algorithms have limitations of complexity,
requirement of signal knowledge and detection performance. In this paper the performance of
eigenvalue based detection (EBD) method in presence of noise and low SNR of the received signal has
been evaluated for a single user.
IOSR Journal of Electronics and Communication Engineering(IOSR-JECE) is an open access international journal that provides rapid publication (within a month) of articles in all areas of electronics and communication engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electronics and communication engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
TARGET LOCALIZATION IN WIRELESS SENSOR NETWORKS BASED ON RECEIVED SIGNAL STRE...sipij
We consider the problem of localizing a target taking the help of a set of anchor beacon nodes. A small
number of beacon nodes are deployed at known locations in the area. The target can detect a beacon
provided it happens to lie within the beacon’s transmission range. Thus, the target obtains a measurement
vector containing the readings of the beacons: ‘1’ corresponding to a beacon if it is able to detect the
target, and ‘0’ if the beacon is not able to detect the target. The goal is twofold: to determine the location
of the target based on the binary measurement vector at the target; and to study the behaviour of the
localization uncertainty as a function of the beacon transmission range (sensing radius) and the number of
beacons deployed. Beacon transmission range means signal strength of the beacon to transmit and receive
the signals which is called as Received Signal Strength (RSS). To localize the target, we propose a gridmapping
based approach, where the readings corresponding to locations on a grid overlaid on the region
of interest are used to localize the target. To study the behaviour of the localization uncertainty as a
function of the sensing radius and number of beacons, extensive simulations and numerical experiments
are carried out. The results provide insights into the importance of optimally setting the sensing radius and
the improvement obtainable with increasing number of beacons.
MULTI-STAGES CO-OPERATIVE/NONCOOPERATIVE SCHEMES OF SPECTRUM SENSING FOR COGN...ijwmn
Searching for spectrum holes in practical wireless channels where primary users experience multipath
fading and shadowing, with noise uncertainty, limits the detection performance significantly. Moreover, the
detection challenge will be tougher when different band types have to be sensed, with different signal and
spectral characteristics, and probably overlapping spectra. Besides, primary user waveforms can be known
(completely or partially) or unknown to allow or forbid cognitive radios to use specific kinds of detection
schemes! Hidden primary user’s problem, and doubly selective channel oblige the use of cooperative
sensing to exploit the spatial diversity in the observations of spatially located cognitive radio users.
Incorporated all the aforementioned practical challenges as a whole, this paper developed a new multistage detection scheme that intelligently decides the detection algorithm based on power, noise, bandwidth
and knowledge of the signal of interest. The proposed scheme switches between individual and cooperative
sensing and among featured based sensing techniques (cyclo-stationary detection and matched filter) and
sub-band energy detection according to the characteristics of signal and band of interest.Compared to the
existing schemes, performance evaluations show reliable results in terms of probabilities of detection and
mean sensing times under the aforementioned conditions.
Effective range free localization scheme for wireless sensor networkijmnct
Location aware sensors can be used in many areas such as military and civilian applications. Wireless
Sensor Networks help to identify the accurate location of the event. In this paper a cost effective schema for
localization has been proposed. It uses two beacon nodes to identify the location of unknown nodes. It
also uses flooding and estimating method to accurately identify the location of other nodes. Available area
is divided into zones and beacons are provided for each zone. Beacon nodes are placed in appropriate
locations normally two in a zone to provide location information. Using the two nodes location of unknown
nodes can be calculated accurately.
Simulation of Direct Sequence Spread Spectrum for Wireless Communication Syst...ijtsrd
In this work, a simulation model for Direct Sequence Spread Spectrum (DSSS) scheme for wireless communication systems has been proposed. Unlike the case of a single frequency carrier, the modulated signal in DSSS occupies a much wider bandwidth in order to reduce the possible interferences with narrow band communication signals. In telecommunications, DSSS is a spread spectrum modulation technique used to reduce overall signal interference. The spreading of this signal makes the resulting wideband channel more noisy, allowing for greater resistance to unintentional and intentional interference. Y.V.S Durga Prasad | K. Venkateswarlu"Simulation of Direct Sequence Spread Spectrum for Wireless Communication Systems using Simulink" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-4 , June 2018, URL: http://www.ijtsrd.com/papers/ijtsrd14118.pdf http://www.ijtsrd.com/engineering/electronics-and-communication-engineering/14118/simulation-of-direct-sequence-spread-spectrum-for-wireless-communication-systems-using-simulink/yvs-durga-prasad
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
PARTICLE FILTER APPROACH TO UTILIZATION OF WIRELESS SIGNAL STRENGTH FOR MOBIL...ijwmn
For many autonomous robotic applications, the capability to simultaneously create a map of the environment while localizing its position within it is of critical importance. This is typically achieved by fusing odometry information from the robotic vehicle with information from landmarks detected within the
environment. Indoor environments often have existing wireless infrastructure, which can be used as landmarks by estimating the distance between the robot and the access point. The most practical way to attain this is by measuring the decay of signal strength. However, radio signal strength does not predictably attenuate indoors as it does in open environments due to signal interference, absorption, and reflection from objects within the environment, inflicting unexpected amplification or decay at the receiver known as multipath interference. This causes erroneous distance estimations due to the unexpected changes
in signal strength attenuation. In this research, models of radio propagation as it relates to the received signal strength indicator (RSSI) are explored along with localization techniques which utilize these models. For development and testing of RSSI-based localization techniques, a simulation method has been
described which utilizes a Markov chain to provide realistic multipath interference on simulated RSSI data. Using this simulation technique, methods for simultaneous localization and mapping (SLAM) are explored. Due to the difficulty associated with modeling RSSI attenuation and distance estimation, a particle filter based SLAM approach is proposed and demonstrated.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
The peer-reviewed International Journal of Engineering Inventions (IJEI) is started with a mission to encourage contribution to research in Science and Technology. Encourage and motivate researchers in challenging areas of Sciences and Technology.
Supercapacitors or EDLCs (i.e. electric double-layer capacitors) or ultra-capacitors are becoming increasingly popular as alternatives for the conventional and traditional battery sources. This brief overview focuses on the different types of supercapacitors, the relevant quantitative modeling areas and the future of supercapacitor research and development. Supercapacitors may emerge as the solution for many application-specific power systems. Especially, there has been great interest in developing supercapacitors for electric vehicle hybrid power systems, pulse power applications, as well as back-up and emergency power supplies. Because of their flexibility, however, supercapacitors can be adapted to serve in roles for which electrochemical batteries are not as well suited. Also, supercapacitors have some intrinsic characteristics that make them ideally suited to specialized roles and applications that complement the strengths of batteries. In particular, supercapacitors have great potential for applications that require a combination of high power, short charging time, high cycling stability and long shelf life. So, let’s just begin the innovative journey of these near future of life-long batteries that can charge up almost anything and everything within a few seconds!
Vehicle routing problem is a NP-hard problem, with the expansion of problem solving more difficult.
This paper proposes a hybrid behavior based on ant colony algorithm to solve the problem, ant to different
objectives in the first place as the path selection according to the analysis of the impact on the algorithm, then
define the ant behavior and design four concrete ant behavior by selecting different ways of ant behavior to
form different improved algorithm. Finally, experimental results show that the improved algorithm can solve
vehicle routing problems quickly and effectively.
Face forward organization – helping victims of domestic abuseChrisgeitz
Face Forward does not have a short term mission to merely assist victims of domestic violence with financial and medical help; it has a long term mission of uprooting domestic violence from every nook and cranny.
GMP helps in providing quality standard product. Subpart - E is related to Control of Components and Drug product containers and closures. Subpart - F is related to Production and Process control.
Desenvolvimento da competência leitora e interpretativa através de jogos educ...José Carlos Afonso
Este objeto de aprendizagem foi elaborado como atividade para a disciplina de Informática Educativa I do curso de Especialização " Novas Tecnologias para o Ensino da Matemática " da Universidade Federal Fluminense - UFF
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Good quality Journals,
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Performance Analysis of Fault Detection in Round Trip Delay and Path Wireless...Editor IJMTER
In recent years, wsns detect to the fault sensor node based on round trip delay using path
in wireless sensor networks. Portable sensor node is low cost in Wsns . Measured in the round trip
delay time and number of sensor node. Existing method is used to large value of sensor node,
identification of sensor node time and distance . it is used to linear selection path, disadvantages are
data loss, more number of path, complexity. in this proposed method using distributed autonomous
sensor software implementation in NS2.it is detected fault sensor node and malfunction ,in this
analysis time and path using discrete Rtp. real time applicability in received signal strength ,separate
wavelength for end of the node avoid the data loss and complexity. Hardware implementation using
ZigBee and Microcontroller .Equal to the hardware and software implementation. It is overcomes to
the data loss. comparing the threshold and Rtd time. Finally, the algorithm is tested under different
number of faulty sensors in the same area. Our Simulation results demonstrate that the time
consumed to find out the faulty nodes in our proposed algorithm is relatively less with a large
number of faulty sensors existing in the network.
An Adaptive Mobility Based Attack Detection Mechanism to Detect Selective For...paperpublications3
Abstract: In this paper propose Mobile network based attack detection of Selective Forwarding Attacks in Wireless Sensor Networks. In existing method only used static network and mobility network require high energy and time. So these problems can be overcome by using Mobile network based attack detection. The wireless sensor network has become a hot research area due its wide range of application in military and civilian domain, but as it uses wireless media for communication these are easily prone to security attacks. Selective forwarding attacks are most effective when the attacker is explicitly included on the path of a data flow. Selective forwarding and black hole attacks are very disastrous attacks for sensor networks if used with sinkhole attack because the intruder can drop most of the important packets. Moreover, the technique involves energy efficiency, reliability and scalability. Simulation results demonstrate that our proposed method can accurately detect selective forwarding attacks and identify the compromised sensor nodes. Experimental result show analytically and through simulation experiments that our schemes achieve effective and robust detection capability with reasonable overheads.
Keywords: Wireless Sensor Network, Selective Forwarding attack, Reputation System, Packet Dropping, Channel-aware, Routing.
Title: An Adaptive Mobility Based Attack Detection Mechanism to Detect Selective Forwarding Attack in Wireless Sensor Network
Author: S.K.Shaju, R.Isaac Sajan, Bibin Christopher, Dr. A.J.Deepa
ISSN 2350-1022
International Journal of Recent Research in Mathematics Computer Science and Information Technology
Paper Publications
Node Deployment in Homogeneous and Heterogeneous Wireless Sensor NetworkIJMTST Journal
Optimal sensor deployment is necessary condition in homogeneous and heterogeneous wireless sensor
network. Effective deployment of sensor nodes is a major point of concern as performance and lifetime of any
WSN. Proposed sensor deployment in WSN explore every sensor node sends its data to the nearest sink node
of the WSN. In addition to that system proposes a hexagonal cell based sensor deployment which leads to
optimal sensor deployment for both homogeneous and heterogeneous sensor deployment. Wireless sensor
networks are receiving significant concentration due to their potential applications ranging from surveillance
to tracking domains. In limited communication range, a WSN is divided into several disconnected sub-graphs
under certain conditions. We deploy sensor nodes at random locations so that it improves performance of the
network.This paper aims to study, discuss and analyze various node deployment strategies and coverage
problems for Homogeneous and Heterogeneous WSN.
EFFECTIVE AND SECURE DATA COMMUNICATION IN WSNs CONSIDERING TRANSFER MODULE O...IJEEE
A Bio-inspired clustering algorithm based on BFO has been proposed and investigation on energy efficient clustering algorithms related to WSNs has been done in this paper. The contribution of this paper related to use of Bacteria foraging algorithm firstly for WSNs for enhancing network lifetime of sensor nodes.
DATA TRANSMISSION IN WIRELESS SENSOR NETWORKS FOR EFFECTIVE AND SECURE COMMUN...IJEEE
Data transmission occurs from transmitting node to sink node, which communicate each other via large number of intermediate nodes or directly to an external base station. A network consists of numbers of nodes with one as a source and one or more as a destination node.
A Comparison of Routing Protocol for WSNs: Redundancy Based Approach A Compar...ijeei-iaes
Wireless Sensor Networks (WSNs) with their dynamic applications gained a tremendous attention of researchers. Constant monitoring of critical situations attracted researchers to utilize WSNs at vast platforms. The main focus in WSNs is to enhance network localization as much as one could, for efficient and optimal utilization of resources. Different approaches based upon redundancy are proposed for optimum functionality. Localization is always related with redundancy of sensor nodes deployed at remote areas for constant and fault tolerant monitoring. In this work, we propose a comparison of classic flooding and the gossip protocol for homogenous networks which enhances stability and throughput quiet significantly.
CODE AWARE DYNAMIC SOURCE ROUTING FOR DISTRIBUTED SENSOR NETWORKIJNSA Journal
Sensor network facilitates monitoring and controlling of physical environments. These wireless networks consist of dense collection of sensors capable of collection and dissemination of data. They have application in variety of fields such as military purposes, environment monitoring etc. Typical deployment of sensor network assumes central processing station or a gateway to which all other nodes route their data using dynamic source routing (DSR). This causes congestion at central station and thus reduces the efficiency of the network. In this work we will propose a better dynamic source routing technique using network coding to reduce total number of transmission in sensor networks resulting in better efficiency.
Complete report on DATA ACQUISITION SCHEME IN WIRELESS SENSOR NETWORKRutvik Pensionwar
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Optimum Sensor Node Localization in Wireless Sensor Networkspaperpublications3
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IOSR Journal of Electronics and Communication Engineering(IOSR-JECE) is an open access international journal that provides rapid publication (within a month) of articles in all areas of electronics and communication engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electronics and communication engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Modified Coverage Hole Detection Algorithm for Distributed WSNsidescitation
Wireless sensor networks (WSNs) are spatially
distributed sensors that find wide applications in various fields
such as environmental control, Medicine and Health care,
Military surveillance etc. The sensing and communication
within the network should be effective for such applications.
Holes are the voids created in the network when accidental
death of nodes is caused due to technical
or improper
coverage. The detection of the holes becomes essential after
the random deployment. The main objective of the work is to
detect the coverage holes using computational geometry
approach which uses co-ordinates of the sensors and to
implement it in the hardware. The communication range of a
node is considered to be equal to its sensing range. The protocol
is designed for irregular domain which is a real time scenario
and takes the help of two-hop neighbors’ of a node to detect
the hole around it. The proposed system also allows only few
nodes to initiate the detection algorithm so that the energy
and time is conserved.
Impact of Next Generation Cognitive Radio Network on the Wireless Green Eco s...ijeei-iaes
Land mobile communication is burdened with typical propagation constraints due to the channel characteristics in radio systems.Also,the propagation characteristics vary form place to place and also as the mobile unit moves,from time to time.Hence,the tramsmission path between transmitter and receiver varies from simple direct LOS to the one which is severely obstructed by buildings, foliage and terrain. Multipath propagation and shadow fading effects affect the signal strength of an arbitrary Transmitter-Receiver due to the rapid fluctuations in the phase and amplitude of signal which also determines the average power over an area of tens or hundreds of meters. Shadowing introduces additional fluctuations, so the received local mean power varies around the area –mean. The present paper deals with the performance analysis of impact of next generation wireless cognitive radio network on wireless green eco system through signal and interference level based k coverage probability under the shadow fading effects.
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Indoor Localization in Wireless Sensor Networks
1. International Journal of Engineering Inventions
e-ISSN: 2278-7461, p-ISSN: 2319-6491
Volume 4, Issue 03 (August 2014) PP: 39-44
www.ijeijournal.com Page | 39
Indoor Localization in Wireless Sensor Networks
Farhat M. A. Zargoun1, Nesreen I. Ziedan1, and Ibrahim M. Henawy2,
Muamer K. Masoud3
1Computer and systems Engineering dept., Faculty of Engineering, Zagazig University
2Faculty of computer and information, Zagazig University
3Computer science dept., Faculty of Science, Zaitoona University
ABSTRACT: Popularity of ubiquitous computing increases the importance of location-aware applications,
which increases the need for finding location of the user. In this paper, we present a novel localization method
for indoor environments using Wi-Fi infrastructure.
While localization using Wi-Fi is cost effective, handling the obstructions which are the main cause of
signal propagation error in indoor environments is a challenging task. We address this problem in two levels,
resulting in increased accuracy of localization. In the first level, we "localize" the residing area of user node in
coarse granularity. Then, we use building layout to find the objects that attenuate the signal between the
reference node and the coarse estimate of the location of user node. Using multi-wall propagation model, we
apply corrections for all obstructions and find the location of user node. Empirical results based on experiments
conducted in lab-scale, shows meter-level accuracy.
I. Introduction
The definition of a localization system among sensor nodes is an important issue for many
applications of wireless sensor networks (WSNs). Thus, a localization system is required in order to provide
position information to the nodes. The importance of localization information arises from several factors, many
of which are related only to WSNs. These factors include the identification and correlation of gathered data,
node addressing, management and query of nodes localized in a determined region, evaluation of nodes’
coverage, energy map generation, geographic routing, object tracking. All of these factors make localization
systems a key technology for the development and operation of WSNs.
To date, a broad variety of positioning techniques has been proposed, the measurement procedures, and
their consideration of application-specific requirements.
For the design and maintenance of indoor wireless services the knowledge of the signal propagation in different
environments is demanded. Indoor propagation is one of the most complicated propagation topics based on the
specific type of the building structure and used materials. Empirical modeling based on statistics seems to be the
most efficient approach since there is no need of precise definition of the building interiors. On the other hand,
such models can fail in indoor situations where more precise site-specific model should be used.
The major source of error for localization using 802.11x infrastructures in indoor environments is the
obstructions that interfere with the signal propagation from the reference node to user node. The attenuation
caused is dependent on the number and type of obstructions. The accuracy of the localization method can be
increased if these obstructions are identified and necessary corrections are applied to the signal strength during
distance estimation. But the actual number and type of obstructions between user node and the reference node
depends on the exact location of user node, which is normally unknown. To overcome this problem, a two level
system is proposed. The two levels in the proposed system are: Coarse level and Fine level. In Coarse level, the
Locality of user node using range-free technique is computed. Then the number and type of obstructions are
found using the computed Locality and knowledge of the building layout. In fine level corrections to the signal
strength are applied using the obstructions found, which are then fed to range-based technique to find the
location of user node.
II. Principles of RSSI ranging
Most widely used propagation model for indoor environments is log distance path loss model, which is given as:
( ) ( ) 10 log ( / ) 0 10 0 RSS d P PL d d d t
μ is the path loss exponent.
The above equation is best suited for obstruction free environments but not for indoor environments
where obstructions are found.
To consider the effect of obstructions on the signal strength, multi-wall propagation model is used; the
generalized propagation model can then be given as:
2. Indoor Localization in Wireless Sensor Networks
www.ijeijournal.com Page | 40
( ) ( ) ( ) 0 RS d P PL d TL d t
TL(d) is represent the total transmission loss, which is consists of two components:
- Path transmission loss (PL(d))
- Loss due to obstructions (OL)
Obstruction Loss {OL) depends on the number of obstructions between the transmitter and the receiver and
is sum of attenuations which is given as:
n
i
i i OL m x
1
mi - number of obstructions
xi – attenuation caused by it.
Note: OL drops to zero when LOS condition exists.
Therefore multi wall propagation model is given as:
n
i
i i RSS d P PL d d d m x
1
0 10 0 ( ) ( ) 10 log ( / )
The parameter xi for each type of obstruction was determined empirically from a series of experiments
conducted under controlled conditions.
We conducted two experiments, one to show that log normal propagation model holds good when there
is line of sight between sender and receiver and the second one to understand the effect of obstruction on the
signal from sender to receiver.
LOS Propagation Model NLOS Propagation Model
The experimental setup for these two experiments is one access point and one laptop were taken, of
which access point was the reference node and the laptop was user node. Xirrus Wi-Fi Inspector software was
installed in user node which captured the signal strength of the broadcast messages sent by the reference node.
The signal strength readings were measured at various distances from the reference node. In LOS experimental
setup, Line of Sight condition exists between the reference node and user node, where as in NLOS setup, an
obstruction was kept between the reference node and user node to find the attenuation loss of this obstruction.
III. System Model
The proposed system requires the storage of the building layout and the attenuation loss of the
obstructions present in the building.
Free space path loss model
3. Indoor Localization in Wireless Sensor Networks
www.ijeijournal.com Page | 41
Path loss exponent, n for different environments
Best fit curve of the average curves of the attenuation loss factor at 2.4 GHz
Wall material Thickness First Wall Second wall
Concrete 10 cm 16 dB 14 dB
Concrete 20 cm 29 dB 24 dB
Dry concrete 35 dB 29 dB
Porous concrete 34 dB 26 dB
Plywood 0.4 cm 0.9 dB 0.8 dB
Penetration loss values for different material characteristics
IV. First level (Coarse level)
Coarse level applies range-free technique to estimate the Locality of user node. Range-free technique
uses the overlapping coverage region of reference nodes to estimate the required area. The reference nodes
having IDs – ID1 to IDn are situated at positions (X1 Y1) to (Xn, Yn) with transmission ranges R1 to Rn
respectively. These reference nodes broadcast messages periodically which contain their ID and location
coordinates. User node listens for these broadcast messages for a period of time and lists the reference nodes
which it is able to hear. User node can receive the broadcast messages of the reference node if and only if it is in
the coverage region of the reference node, which is the circle drawn with the reference node location as the
center and its transmission range as the radius. If user node is able to hear from more than one reference node,
then the overlapping coverage region of all these reference nodes correspond to the Locality of user node. Here
it has to be observed that the signal strength of the messages from the reference node is not being taken into
consideration, so the accuracy of the returned Locality will not be affected by the attenuation error caused by the
obstructions.
4. Indoor Localization in Wireless Sensor Networks
www.ijeijournal.com Page | 42
Intersection Approach Cell Table
The whole operating environment is divided into cells, where each square represents one cell. Each cell
is assigned an integer called cell rank which is set to zero initially for all the cells. This cell rank represents the
number of reference nodes in its range. Each cell is checked for the validation of In-range property to decide if
the cell is included in the transmission range of the reference node. If the cell satisfies this property, the rank of
the cell is incremented by one otherwise the value remains unchanged. This process is repeated for all the
reference nodes from which user node has received the broadcast messages.
The In-Range property checks whether the cell is in the coverage region of the corresponding reference
node or not, which can be formulated as below:
The pseudo code for Cell Ranking is as follows:
For each cell C of the building
For each reference node IDj user node is hearing
If ( )
Then increment cell rank by 1;
V. Second level (Fine level)
Fine level estimates the cell in which user node is residing from the set of cells obtained in coarse level.
Most of the error in indoor environments is due to the attenuation caused by obstructions between the
transmitter and the receiver. If the number of obstructions between the reference node and user node were
known, then the distance to the reference node can be determined using the multi-wall propagation model
equation by applying the correction. However, the actual number of obstructions between the reference node
and user node depends on the exact location of user node then it is unknown. To circumvent this problem, for all
the cells obtained in the coarse level, signal strength vector is estimated by finding the obstructions and using
multi-wall propagation model equation, which is then compared with the received signal strength vector. The
location of user node is defined as the center of the cell whose estimated signal strength vector best matches
with the received signal strength vector.
Consider the layout plan shown in the Figure below, where reference nodes are shown as A1, A2 and
A3 and square C represents one of the cells obtained from the coarse level. The obstructions between cell C and
each of the reference nodes can be determined as the positions of cell, reference nodes and layout plan is known.
Taking this information into consideration signal strength vector is estimated using Multi-wall propagation
equation.
Building Layout
5. Indoor Localization in Wireless Sensor Networks
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This signal strength vector is estimated for each cell obtained from the coarse level. It is of the form
SI= (SI1,SI2,SI3,.. ..,SIK), for all I=1 to N, where N is number of cells obtained in coarse level and k is the number
of reference nodes covering the obtained cells and SIJ denotes the signal strength at cell i from the Jth reference
node.
The received signal strength vector is represented as R= (r1, r2, r3,....,rk). The Euclidean distance given
in the following equation is calculated between the received signal strength vector and the estimated signal
strength vector for all the cells.
k
j
i ij j D S R S r
1
2 ( , ) ( )
The Cell Number with minimum Euclidean distance is found as shown in the following equation,
whose center is taken as the location of user node.
Cell Number = min [D (SI, R)]
VI. The Experiment
A series of experiments were done under controlled conditions to evaluate the performance of this
work. All the experiments are conducted in two-dimensions by keeping all the reference nodes and user node at
the same height.
The considered infrastructure contains four reference nodes and one user node. The reference nodes
were static.
Xirrus Wi-Fi Inspector software package was installed in user node to capture the signal strength of the
messages sent by the reference nodes, or you can install any another Wi-Fi inspector softwar. The building was
divided into cells of size 0.9 x 0.9 m. User moved along various cells and measured both the actual position and
signal strength readings from the reference nodes. The location of user node was estimated with these signal
strength vectors using the proposed two-level approach. The location estimation error was calculated as the
distance between the actual location and estimated location. Let (x, y) represent the actual location and (xest, yest)
represent the estimated location. The error is given by:
2 2 Error x x (y y) est est
VII. Simulation Results
Simulation was done to see the effect of number of reference nodes and size of cell on location
accuracy. Size of the building was taken as 60x30 m2 and parameter values of the multi-wall propagation model
used are given in Table below. A random noise with δ2 =4 dB was added to the model and positions of the
reference nodes and user nodes were selected inside the building.
d0 1 meter
Pt –PL(d0) -38 dBm
μ 2.5
R 30 meter
Table: Parameter values for propagation model
6. Indoor Localization in Wireless Sensor Networks
www.ijeijournal.com Page | 44
The graph in Figure below shows the location error for various points. The x-axis shows various points in the building and the y-axis shows error in meters. It can be observed from this Figure that the error of the proposed technique is less than 2 meter for all the cells.
VIII. Conclusions
In this work we have proposed a technique which works in two levels using both range-free and range- based techniques in a sequence. This work uses the range-free technique to find the Locality of user node and then use multi-wall propagation model inside this Locality to find out the exact position. This work provides improved accuracy because we are using multi-wall propagation model which corrects the attenuation caused by obstructions in the building. We have shown through experiments that the error obtained is less than two meters, which is appreciable, as the exact location is estimated from the Locality identified by the coarse-level part of the This work as opposed to considering the whole operating environment. References
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