Due to the lack of accurate evaluation of the transmission characteristics of the wireless communication links, routing algorithms in wireless sensor networks may result in poor network performance. In order to avoid sending packets over the unstable link, routing protocol has to rely on noble metrics to choose better routing path. Better estimation of link reliability between neighboring nodes could permit the selection of a more reliable route. Since the routing metrics play an important role as they have a direct impact on the efficiency and robustness of routing protocols. Different routing metrics will provide different performances to routing protocols when used to compute weight of paths. This paper presents a study on various hardware and software link quality metrics that
help network protocol designers can choose an efficient Link Quality Estimator to develop reliable routing techniques for WMSNs. Additionally a classification tree of different routing metrics is presented which helps in understanding the strengths and weaknesses of these LQ metrics, thus enabling the designer of the routing protocol to make an informed choice.
Secure and reliable routing protocols for heterogeneous multihop wireless net...Pvrtechnologies Nellore
E-STAR combines payment and trust systems with an energy-aware and trust-based routing protocol to establish stable and reliable routes in heterogeneous multi-hop wireless networks. The payment system rewards nodes for relaying packets and the trust system evaluates nodes' reliability through multi-dimensional trust values. Two routing protocols direct traffic along routes with highly trusted nodes that have sufficient energy, minimizing broken routes. This stimulates cooperation and maintains stability. Analysis shows E-STAR secures payment and trust calculation without false accusations, and simulation shows it improves delivery ratio and stability.
Congestion control in packet switched wide area networks using a feedback modelijcses
In a complex world, where networking expands very rapidly, the network stability of flow of bandwidth
played a vital role in transmitting packets. Hence, it was imperative to find solution to the problem of
congestion especially in the follow of bandwidth stability.
Congestion in computer networking is caused by so many factors. Some of the signs are packet loss,
queuing delay resulting from overloading the buffer, faulty hardware devices, intermixing of old and new
technologies and unstable flow of bandwidth resulting from positive feedback
Internet Traffic Classification Using Bayesian Analysis TechniquesDenis Zuev
This document discusses using Bayesian analysis techniques to classify internet traffic by application. Specifically, it uses a Naive Bayes estimator trained on hand-classified network data to categorize traffic. The results show this simple Naive Bayes estimator can achieve about 65% accuracy on per-flow classification, which can be improved to over 95% accuracy using two refinements to the estimator. The approach uses training data with categories derived from packet content but classifies testing data using only header-derived discriminators, demonstrating traffic can be categorized using commonly available information.
Enhance the Throughput of Wireless Network Using Multicast RoutingIOSR Journals
Wireless Mesh Network is designed static or limited mobility environment .In multicast routing for
wireless mesh networks has focused on metrics that estimate link quality to maximize throughput
andtoprovide secure communication. Nodes must collaborate in order to compute the path metric and
forward data.Node identify the novel attacks against high- throughput multicast protocols in wireless
mesh network.. The attacks exploit the local estimation and global aggregation of the metric to allow
attackers to attract a large amount of traffic These attacks are very effective b a s e d on high
throughput metrics. The aggressive path selection is a double-edged sword: It is maximizes throughput,
it also increases attack effectiveness. so Rate guard mechanism will be used.Rate guard mechanism
means combines Measurement-based detection and accusation-based reaction techniques.The attacks
and the defense using ODMRP, a representative multicast protocol for wireless mesh networks, and
SPP, an adaptation of the well-known ETX unicast metric to the multicast setting
Impact analysis of epda and ipda attack with increasing node mobility in data...eSAT Journals
Abstract In this Paper, two types of denial of service attacks over mobile ad hoc networks are implemented and their impact is analyzed on data communication process when using a reactive routing protocol for data communication. The reactive routing protocol well known Ad-hoc on-demand distance vector (AODV) routing protocol. In the Implemented attacks, a malicious node i.e., attacker will drop data packets that it receives for forwarding towards the destination of the packet. The attacker can do the attack by either making itself one of the intermediate nodes on the active route. The attackers can be one of the intermediate nodes in two ways. In the first method the attacker is waiting that some route discovery process will select it as one of its intermediate node and then it will drop all the data packets it receives for forwarding to destination. In the second method the attacker uses the dissemination of the false information to become the part of an active route. Due to the wrong information spread by the malicious nodes the routing tables of the source node enters a route for the destination that will surely includes the attacker in the route. The Implemented attack is simulated using a tool Exata and results are drawn using graphs to show the impact of the attack on data communication. Finally, a mechanism is proposed through which both the attack and attackers can be detected during the data communication and can be avoided in further communication process. Keywords: AODV, DoS Attacks, EPDA & IPDA Attacks, MANET
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
In this paper, an application-based QoS evaluation approach for heterogeneous networks is proposed.It is possible to expand the network capacity and coverage in a dynamic fashion by applying heterogeneous wireless network architecture. However, the Quality of Service (QoS) evaluation of this type of network architecture is very challenging due to the presence of different communication technologies. Different communication technologies have different characteristics and the applications that utilize them have unique QoS requirements. Although, the communication technologies have different performance measurement parameters, the applications using these radio access networks have the same QoS requirements. As a result, it would be easier to evaluate the QoS of the access networks and the overall network configuration based on the performance of applications running on them. Using such applicationbased QoS evaluation approach, the heterogeneous nature of the underlying networks and the diversity of their traffic can be adequately taken into account. Through simulation studies, we show that the application performance based assessment approach facilitates better QoS management and monitoring of heterogeneous network configurations.
This document discusses implementing trust-based route selection in mobile ad hoc networks. It proposes a system to store and update trust values for nodes based on their behavior. Different strategies are designed to evaluate routes based on the trust values of their constituent nodes. The performance of applying trust-based route selection to DSR, AODV and DYMO routing protocols is evaluated using the QualNet simulator in terms of metrics like throughput, packet delivery ratio and average jitter. The evaluation aims to improve routing performance and security in the presence of malicious nodes.
Secure and reliable routing protocols for heterogeneous multihop wireless net...Pvrtechnologies Nellore
E-STAR combines payment and trust systems with an energy-aware and trust-based routing protocol to establish stable and reliable routes in heterogeneous multi-hop wireless networks. The payment system rewards nodes for relaying packets and the trust system evaluates nodes' reliability through multi-dimensional trust values. Two routing protocols direct traffic along routes with highly trusted nodes that have sufficient energy, minimizing broken routes. This stimulates cooperation and maintains stability. Analysis shows E-STAR secures payment and trust calculation without false accusations, and simulation shows it improves delivery ratio and stability.
Congestion control in packet switched wide area networks using a feedback modelijcses
In a complex world, where networking expands very rapidly, the network stability of flow of bandwidth
played a vital role in transmitting packets. Hence, it was imperative to find solution to the problem of
congestion especially in the follow of bandwidth stability.
Congestion in computer networking is caused by so many factors. Some of the signs are packet loss,
queuing delay resulting from overloading the buffer, faulty hardware devices, intermixing of old and new
technologies and unstable flow of bandwidth resulting from positive feedback
Internet Traffic Classification Using Bayesian Analysis TechniquesDenis Zuev
This document discusses using Bayesian analysis techniques to classify internet traffic by application. Specifically, it uses a Naive Bayes estimator trained on hand-classified network data to categorize traffic. The results show this simple Naive Bayes estimator can achieve about 65% accuracy on per-flow classification, which can be improved to over 95% accuracy using two refinements to the estimator. The approach uses training data with categories derived from packet content but classifies testing data using only header-derived discriminators, demonstrating traffic can be categorized using commonly available information.
Enhance the Throughput of Wireless Network Using Multicast RoutingIOSR Journals
Wireless Mesh Network is designed static or limited mobility environment .In multicast routing for
wireless mesh networks has focused on metrics that estimate link quality to maximize throughput
andtoprovide secure communication. Nodes must collaborate in order to compute the path metric and
forward data.Node identify the novel attacks against high- throughput multicast protocols in wireless
mesh network.. The attacks exploit the local estimation and global aggregation of the metric to allow
attackers to attract a large amount of traffic These attacks are very effective b a s e d on high
throughput metrics. The aggressive path selection is a double-edged sword: It is maximizes throughput,
it also increases attack effectiveness. so Rate guard mechanism will be used.Rate guard mechanism
means combines Measurement-based detection and accusation-based reaction techniques.The attacks
and the defense using ODMRP, a representative multicast protocol for wireless mesh networks, and
SPP, an adaptation of the well-known ETX unicast metric to the multicast setting
Impact analysis of epda and ipda attack with increasing node mobility in data...eSAT Journals
Abstract In this Paper, two types of denial of service attacks over mobile ad hoc networks are implemented and their impact is analyzed on data communication process when using a reactive routing protocol for data communication. The reactive routing protocol well known Ad-hoc on-demand distance vector (AODV) routing protocol. In the Implemented attacks, a malicious node i.e., attacker will drop data packets that it receives for forwarding towards the destination of the packet. The attacker can do the attack by either making itself one of the intermediate nodes on the active route. The attackers can be one of the intermediate nodes in two ways. In the first method the attacker is waiting that some route discovery process will select it as one of its intermediate node and then it will drop all the data packets it receives for forwarding to destination. In the second method the attacker uses the dissemination of the false information to become the part of an active route. Due to the wrong information spread by the malicious nodes the routing tables of the source node enters a route for the destination that will surely includes the attacker in the route. The Implemented attack is simulated using a tool Exata and results are drawn using graphs to show the impact of the attack on data communication. Finally, a mechanism is proposed through which both the attack and attackers can be detected during the data communication and can be avoided in further communication process. Keywords: AODV, DoS Attacks, EPDA & IPDA Attacks, MANET
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
In this paper, an application-based QoS evaluation approach for heterogeneous networks is proposed.It is possible to expand the network capacity and coverage in a dynamic fashion by applying heterogeneous wireless network architecture. However, the Quality of Service (QoS) evaluation of this type of network architecture is very challenging due to the presence of different communication technologies. Different communication technologies have different characteristics and the applications that utilize them have unique QoS requirements. Although, the communication technologies have different performance measurement parameters, the applications using these radio access networks have the same QoS requirements. As a result, it would be easier to evaluate the QoS of the access networks and the overall network configuration based on the performance of applications running on them. Using such applicationbased QoS evaluation approach, the heterogeneous nature of the underlying networks and the diversity of their traffic can be adequately taken into account. Through simulation studies, we show that the application performance based assessment approach facilitates better QoS management and monitoring of heterogeneous network configurations.
This document discusses implementing trust-based route selection in mobile ad hoc networks. It proposes a system to store and update trust values for nodes based on their behavior. Different strategies are designed to evaluate routes based on the trust values of their constituent nodes. The performance of applying trust-based route selection to DSR, AODV and DYMO routing protocols is evaluated using the QualNet simulator in terms of metrics like throughput, packet delivery ratio and average jitter. The evaluation aims to improve routing performance and security in the presence of malicious nodes.
Fault Link Detection in WSN using Link Scanner ApproachIRJET Journal
This document proposes a new approach for detecting faulty links in wireless sensor networks. The approach uses the expected transmission count (ETX) metric to calculate link quality and detect links with high packet loss. It also tracks the hop count and path of packets to detect inconsistencies that indicate faulty links. When a faulty link is detected, the approach finds an alternate path to route packets around it. The key components are calculating ETX values, including hop count and node IDs in packet headers, comparing expected vs. actual hop counts, and detecting mismatches to identify faulty links. The goal is to robustly and efficiently detect link failures to maintain network connectivity and avoid packet loss.
Enhancement of qos in multihop wireless networks by delivering cbr using lb a...eSAT Journals
Abstract One of the most complicated issues is to measuring the delay performance of end to end nodes in Multi-hop Wireless Networks. The two nodes are communicating via hopping over the multiple wireless links. The fact that is each node has to concentrate not only its own generated traffic, but also relayed one. Observing unfairness particularly for transmissions among nodes that are more than one hop Most of the existing works deals with the joint congestion control and scheduling algorithm, which does not focusing the delay performance. In turn, considering the throughput metric alone although for congestion control flows, throughput is the repeated difficult performance metric Packet delay is also important because practical congestion control protocols need to establish the timeouts for the retransmissions based on the packet delay, such parameters could significantly impact the speed of recovery when loss of packets occurred. The related issues on the delay-performance First, for long flows, the end to end delay may grow in terms of square with based on the number of hops. Second, it is difficult to control the end-to-end delay of each flows. TDMA schedules the transmissions in a fair way, in terms of throughput per connection, considering the communication requirements of the active flows of the network. It does not work properly in the multi-hop scenario, because it is generated only for single hop networks, We propose The Leaky Bucket Algorithm, in addition to joint congestion control and scheduling algorithm in multi-hop wireless networks. The proposed algorithm not only achieves the provable throughput and also considering the upper bounds of the delay of each flow. It reduces the transmission time by delivering packets at a constant bit rate even it receives the packet at a busty way. Keywords- Multi-hop wireless networks, congestion control, Performance, Delay, Flow, Throughput.
Enhancement of qos in multihop wireless networks by delivering cbr using lb a...eSAT Publishing House
This document summarizes a research paper that proposes using the Leaky Bucket Algorithm to enhance quality of service (QoS) in multi-hop wireless networks delivering constant bit rate (CBR) traffic. The Leaky Bucket Algorithm aims to reduce transmission delay by delivering packets at a constant rate even when packets arrive in bursts. It combines joint congestion control and a scheduling algorithm to not only achieve provable throughput guarantees, but also place explicit upper bounds on the end-to-end delay of each flow. Simulation results show the proposed approach reduces transmission time and improves throughput compared to existing scheduling algorithms that do not consider delay performance.
A survey on trust based secure routing in manetcsandit
A mobile ad hoc network is a wireless network in which no infrastructure is available. MANET is a selfconfiguring
network. Due to dynamic nature of MANET it is very challenging work to employ a secure
route. The intermediate nodes cooperate with each other as there is no such base station or access point.
The routing protocols play important role in transferring data. Cryptographic mechanisms are used in
routing protocols to secure data packets while transmitted in the network. But cryptographic techniques
incur a high computational cost and can’t identify the nodes with malicious intention. So, employing
cryptographic techniques in MANET are quite impractical as MANETs have limited resource and
vulnerable to several security attacks. Trust mechanism is used as an alternative to cryptographic
technique. Trust mechanism secures data forwarding by isolating nodes with malicious intention using trust
value on the nodes. In this paper we survey different trust based protocols of MANET and compare their
performances.
IRJET- Vitality Rooted Modern Trends in Delay Tolerant NetworksIRJET Journal
The document discusses various energy-aware routing techniques for delay tolerant networks (DTNs). It first describes how routing protocols in DTNs do not typically consider energy constraints. It then summarizes two recent energy-aware approaches: 1) A priority transmission scheme that assigns message priorities and manages buffers and transmissions based on nodes' remaining energy levels to improve delivery of high priority messages. 2) A robust epidemic routing protocol that forwards messages only to nodes with higher remaining energy and available buffer space to increase network lifetime. The document stresses the importance of energy-efficient routing techniques for DTNs given devices' limited energy resources.
SECURING BGP BY HANDLING DYNAMIC NETWORK BEHAVIOR AND UNBALANCED DATASETSIJCNCJournal
The Border Gateway Protocol (BGP) provides crucial routing information for the Internet infrastructure. A problem with abnormal routing behavior affects the stability and connectivity of the global Internet. The biggest hurdles in detecting BGP attacks are extremely unbalanced data set category distribution and the dynamic nature of the network. This unbalanced class distribution and dynamic nature of the network results in the classifier's inferior performance. In this paper we proposed an efficient approach to properly managing these problems, the proposed approach tackles the unbalanced classification of datasets by turning the problem of binary classification into a problem of multiclass classification. This is achieved by splitting the majority-class samples evenly into multiple segments using Affinity Propagation, where the number of segments is chosen so that the number of samples in any segment closely matches the minority-class samples. Such sections of the dataset together with the minor class are then viewed as different classes and used to train the Extreme Learning Machine (ELM). The RIPE and BCNET datasets are used to evaluate the performance of the proposed technique. When no feature selection is used, the proposed technique improves the F1 score by 1.9% compared to state-of-the-art techniques. With the Fischer feature selection algorithm, the proposed algorithm achieved the highest F1 score of 76.3%, which was a 1.7% improvement over the compared ones. Additionally, the MIQ feature selection technique improves the accuracy by 3.5%. For the BCNET dataset, the proposed technique improves the F1 score by 1.8% for the Fisher feature selection technique. The experimental findings support the substantial improvement in performance from previous approaches by the new technique.
Ensure Security and Scalable Performance in Multiple Relay NetworksEditor IJCATR
A relay network is a broad class of network topology commonly used in networks, where the source and destination are
interconnected by means of a some nodes. In such a network the source and destination cannot transmit to each other directly because
the distance between the source and destination is greater than the transmission range of both of them, hence the demand for
intermediate node(s) to relay. The problem of detecting malicious relay nodes in single source, multi-relay networks has been studied
in the literature for different relaying schemes. Relay nodes in apply network coding while those in and follow the decode-and-forward
protocol. The authors consider a peer-to-peer (P2P) network in which peers receive and forward a linear combination of the exogenous
data packets. To check out the integrity of the received packets, a key signature vector is generated at the source node and broadcasted
to all nodes where it is used to check the integrity of the received packets. In and several information theoretic algorithms for
mitigating falsified data injection effects are proposed. The network modeling used in these works is composed of a single source,
multiple intermediate nodes which utilize network coding. We consider a multiple access relay network where multiple sources send
independent data to a single destination through multiple relays, which may interject falsified data into the network. To detect the
malevolent relays and dispose (efface) data from them, trace bits are embedded in the information data at each source node.
This document summarizes a research paper on dynamic resource allocation in wireless sensor networks. It proposes a load balancing mechanism that measures traffic load at each access point and shares the communication load among neighboring access points. It also proposes resource allocation for sensor networks that considers uplink and downlink channel information and network path/congestion data. Shortest path and routing algorithms are used to select optimal paths for sending data packets from source to destination nodes via intermediate nodes while dynamically allocating bandwidth. The mechanism aims to improve quality of service parameters like packet delivery, throughput, and efficiency of bandwidth allocation.
Transfer reliability and congestion control strategies in opportunistic netwo...IEEEFINALYEARPROJECTS
The document discusses transfer reliability and congestion control strategies in opportunistic networks. It begins by stating that opportunistic networks have unpredictable node contacts and rarely have complete end-to-end paths. It then discusses how modified TCP protocols are ineffective for these networks and they require different approaches than intermittently connected networks. The document surveys proposals for transfer reliability using hop-by-hop custody transfer and end-to-end receipts. It also categorizes storage congestion control based on single or multiple message copies. It identifies open research issues including replication management and drop policies for multiple copies.
A Secure Payment Scheme with Low Communication and Processing Overhead for Mu...Editor IJMTER
In this proposed work a trust-based routing protocol is developed to route messages through the
highly trusted nodes to minimize the probability of dropping the messages. Thus improve the network
performance in terms of throughput and packet delivery ratio. The proposed design contains a novel secure
reactive routing protocol for Mobile ad hoc networks (MANETs), called TRIUMF (Trust-Based Routing
Protocol with controlled degree of Selfishness for Securing MANET against Packet Dropping Attack). In the
proposed protocol trust among nodes is represented by trust value, which consists of cooperation score, direct
trust and indirect trust. The proposed trust routing allows controlled degree of selfishness to give an incentive to
the selfish nodes to declare its selfishness behavior to its neighbor nodes, which reduce the searching time of
misbehaving nodes to search for the malicious nodes only. In the proposed routing protocol two node-disjoint
routes between the source and destination nodes are selected based on their path trust values, one marked as
primary and the other as secondary. In this work both DLL-ACK and end- to-end TCP-ACK as monitoring
tools to monitor the behavior of routing path nodes: if the data packet successfully transmitted, then the path
nodes trust value are updated positively; otherwise, if a malicious behavior is detected then the path searching
tool starts to identify the malicious nodes and isolate them from the routing path and the network. Finally this
scheme reduces the searching time of malicious nodes, and the routing protocol avoids the isolated misbehaving
node from sharing in all future routes, which improves the overall network throughput.
Maximizing Efficiency Of multiple–Path Source Routing in Presence of JammerIOSR Journals
This paper explores maximizing the efficiency of multiple-path source routing in the presence of a jammer. It implements jamming-aware traffic allocation based on previous work, relaxing the assumption of in-network inference of variable correlations. The source node allocates traffic to paths based on estimated jamming statistics. Portfolio selection theory is used to optimize throughput. Simulation results using NS2 show the network is capable of jamming-aware allocation that increases throughput compared to ignoring jamming.
Mobile environment pretense a number of novel
theoretical and optimization issues such as position, operation
and following in that a lot of requests rely on them for
desirable information. The precedent works are sprinkled
across the entire network layer: from the medium of physical
to link layer to routing and then application layer. In this
invention, we present outline solutions in Medium Access
Control (MAC), data distribution, coverage resolve issues
under mobile ad-hoc network environment based on
congestion control technique using Transmission Control
Protocol (TCP). In mobile ad-hoc network issues can arise
such as link disconnections, channel contention and recurrent
path loss. To resolve this issue, we propose a Cross Layer
based Hybrid fuzzy ad-hoc rate based Congestion Control
(CLHCC) approach to maximize network performance. Based
on the destination report it regulates the speed of data flow to
control data loss by monitoring the present network status
and transmits this report to the source as advice. The source
adjusts the sending flow rate as per the advice. This is
monitored by channel usage, ultimate delay, short term
throughput.
Reliability Evaluation and Analysis of Mobile Ad Hoc Networks IJECEIAES
The paper addresses the reliability problem of mobile ad hoc networks under link and node failure model. Node reliability is calculated as a function of no. of neighbor nodes, packet success rate, and device type and packet size. The presence of a link between any node pair is binary and its reliability is computed considering the distance between nodes and signal-to-noise ratio (SNR). An efficient algorithm is proposed to analyze and calculate the reliability of mobile ad hoc networks considering multiple routes from source and destination nodes. The effect of different parameters on node reliability and link reliability are analyzed and discussed. The network is simulated and analyzed using INET frame work. Reliability of two distinct cases of this simulation is evaluated. The simulated results and discussions ensure that evaluation of the reliability of any mobile ad hoc networks can be done easily and in an efficient manner by the proposed method.
Link Disconnection Entropy Disorder in Mobile Adhoc Networkspaperpublications3
Abstract: In Mobile Ad-hoc Networks, nodes move freely causing an interruption in communications. This communication interruption can be accounted in a time lapse to an entropy to connection or disconnection; the combined entropy disorder of a node’s links describe how suitable a node is to communicate to neighbors. This entropy disorder is tightly coupled to mobility and communications factors such as node’s speed or data traffic saturation. In this paper, we analyze the relationship between speed and traffic saturation into a disorder in link entropy with a focus on disconnection, namely Link Disconnection Entropy Disorder (LDED). The findings indicate a high LDED value to nodes with high speed.
Application-Based QoS Evaluation of Heterogeneous Networks csandit
Heterogeneous wireless networks expand the network capacity and coverage by leveraging the
network architecture and resources in a dynamic fashion. However, the presence of different
communication technologies makes the Quality of Service (QoS) evaluation, management, and
monitoring of these networks very challenging. Each communication technology has its own
characteristics while the applications that utilize them have their specific QoS requirements.
Although, the communication technologies have different performance assessment parameters,
the applications using these radio access networks have the same QoS requirements. As a
result, it would be easier to evaluate the QoS of the access networks and the overall network
configuration depending on the performance of applications running on them. Using such
application-based QoS evaluation approach, the heterogeneous nature of the underlying
networks and the diversity of their traffic can be adequately taken into account. In this paper,
we propose an application-based QoS evaluation approach for heterogeneous networks.
Through simulation studies, we show that this assessment approach facilitates better QoS
management and monitoring of heterogeneous network configurations.
Survey paper on Evaluating Trust and Reputation Using Uncertain Reasoning in ...IJARIIE JOURNAL
This document discusses evaluating trust and reputation using uncertain reasoning in mobile ad hoc networks (MANETs). It first defines trust, reputation, and uncertain reasoning. It then discusses different routing protocols used in MANETs like AODV, OLSR, and DSR. It also discusses security attacks in MANETs and how trust and reputation models can be used to address these issues. Finally, it discusses probabilistic reasoning and Dempster-Shafer theory as ways to handle uncertainty in evaluating trust and reputation.
El documento presenta el programa de un simposio sobre fenomenología. El simposio incluye presentaciones sobre la técnica fenomenológica, el contexto histórico y las características de la fenomenología, así como las etapas del método fenomenológico y una sesión de interacción con un experto invitado. El objetivo es entender el mundo desde la perspectiva subjetiva de quien lo experimenta mediante la descripción y el análisis de casos vividos de manera directa.
Improved Cell Coverage in Hilly Areas using Cellular AntennasEswar Publications
This paper proposes an improved configuration of Cellular Antennas for terrains like hills where network coverage is poor and a number of black spots are very high. The proposed solution delivers efficient and much robust antenna structure which provides better network coverage by using 90-degree sector antennas. The radio spectrum of the 90-degree sector antenna is also shown to give the idea of cell coverage in order to build aseamless network in the region.This paper also proposes different channel allocation schemes that can be used with the proposed antenna configuration to deliver better network coverage and low call dropping probability.
This is achieved by analyzing the terrain of the region and also the cellular traffic in the region. In areas where network traffic is almost constant or have low population, strategies like fixed channel allocation can be used effectively and efficiently. While in the areas where traffic is unpredictable or is subject to regional festivals or tourism, channel strategies like dynamic channel allocation are very useful to fulfill the demand of the overall network. The simulations and validations for the proposed methodology are done using MATLAB.
NetSim (http://www.tetcos.com/) Best Network Simulator , provide wireless sensor network Based IEEE 802.15.4 Standard
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Fault Link Detection in WSN using Link Scanner ApproachIRJET Journal
This document proposes a new approach for detecting faulty links in wireless sensor networks. The approach uses the expected transmission count (ETX) metric to calculate link quality and detect links with high packet loss. It also tracks the hop count and path of packets to detect inconsistencies that indicate faulty links. When a faulty link is detected, the approach finds an alternate path to route packets around it. The key components are calculating ETX values, including hop count and node IDs in packet headers, comparing expected vs. actual hop counts, and detecting mismatches to identify faulty links. The goal is to robustly and efficiently detect link failures to maintain network connectivity and avoid packet loss.
Enhancement of qos in multihop wireless networks by delivering cbr using lb a...eSAT Journals
Abstract One of the most complicated issues is to measuring the delay performance of end to end nodes in Multi-hop Wireless Networks. The two nodes are communicating via hopping over the multiple wireless links. The fact that is each node has to concentrate not only its own generated traffic, but also relayed one. Observing unfairness particularly for transmissions among nodes that are more than one hop Most of the existing works deals with the joint congestion control and scheduling algorithm, which does not focusing the delay performance. In turn, considering the throughput metric alone although for congestion control flows, throughput is the repeated difficult performance metric Packet delay is also important because practical congestion control protocols need to establish the timeouts for the retransmissions based on the packet delay, such parameters could significantly impact the speed of recovery when loss of packets occurred. The related issues on the delay-performance First, for long flows, the end to end delay may grow in terms of square with based on the number of hops. Second, it is difficult to control the end-to-end delay of each flows. TDMA schedules the transmissions in a fair way, in terms of throughput per connection, considering the communication requirements of the active flows of the network. It does not work properly in the multi-hop scenario, because it is generated only for single hop networks, We propose The Leaky Bucket Algorithm, in addition to joint congestion control and scheduling algorithm in multi-hop wireless networks. The proposed algorithm not only achieves the provable throughput and also considering the upper bounds of the delay of each flow. It reduces the transmission time by delivering packets at a constant bit rate even it receives the packet at a busty way. Keywords- Multi-hop wireless networks, congestion control, Performance, Delay, Flow, Throughput.
Enhancement of qos in multihop wireless networks by delivering cbr using lb a...eSAT Publishing House
This document summarizes a research paper that proposes using the Leaky Bucket Algorithm to enhance quality of service (QoS) in multi-hop wireless networks delivering constant bit rate (CBR) traffic. The Leaky Bucket Algorithm aims to reduce transmission delay by delivering packets at a constant rate even when packets arrive in bursts. It combines joint congestion control and a scheduling algorithm to not only achieve provable throughput guarantees, but also place explicit upper bounds on the end-to-end delay of each flow. Simulation results show the proposed approach reduces transmission time and improves throughput compared to existing scheduling algorithms that do not consider delay performance.
A survey on trust based secure routing in manetcsandit
A mobile ad hoc network is a wireless network in which no infrastructure is available. MANET is a selfconfiguring
network. Due to dynamic nature of MANET it is very challenging work to employ a secure
route. The intermediate nodes cooperate with each other as there is no such base station or access point.
The routing protocols play important role in transferring data. Cryptographic mechanisms are used in
routing protocols to secure data packets while transmitted in the network. But cryptographic techniques
incur a high computational cost and can’t identify the nodes with malicious intention. So, employing
cryptographic techniques in MANET are quite impractical as MANETs have limited resource and
vulnerable to several security attacks. Trust mechanism is used as an alternative to cryptographic
technique. Trust mechanism secures data forwarding by isolating nodes with malicious intention using trust
value on the nodes. In this paper we survey different trust based protocols of MANET and compare their
performances.
IRJET- Vitality Rooted Modern Trends in Delay Tolerant NetworksIRJET Journal
The document discusses various energy-aware routing techniques for delay tolerant networks (DTNs). It first describes how routing protocols in DTNs do not typically consider energy constraints. It then summarizes two recent energy-aware approaches: 1) A priority transmission scheme that assigns message priorities and manages buffers and transmissions based on nodes' remaining energy levels to improve delivery of high priority messages. 2) A robust epidemic routing protocol that forwards messages only to nodes with higher remaining energy and available buffer space to increase network lifetime. The document stresses the importance of energy-efficient routing techniques for DTNs given devices' limited energy resources.
SECURING BGP BY HANDLING DYNAMIC NETWORK BEHAVIOR AND UNBALANCED DATASETSIJCNCJournal
The Border Gateway Protocol (BGP) provides crucial routing information for the Internet infrastructure. A problem with abnormal routing behavior affects the stability and connectivity of the global Internet. The biggest hurdles in detecting BGP attacks are extremely unbalanced data set category distribution and the dynamic nature of the network. This unbalanced class distribution and dynamic nature of the network results in the classifier's inferior performance. In this paper we proposed an efficient approach to properly managing these problems, the proposed approach tackles the unbalanced classification of datasets by turning the problem of binary classification into a problem of multiclass classification. This is achieved by splitting the majority-class samples evenly into multiple segments using Affinity Propagation, where the number of segments is chosen so that the number of samples in any segment closely matches the minority-class samples. Such sections of the dataset together with the minor class are then viewed as different classes and used to train the Extreme Learning Machine (ELM). The RIPE and BCNET datasets are used to evaluate the performance of the proposed technique. When no feature selection is used, the proposed technique improves the F1 score by 1.9% compared to state-of-the-art techniques. With the Fischer feature selection algorithm, the proposed algorithm achieved the highest F1 score of 76.3%, which was a 1.7% improvement over the compared ones. Additionally, the MIQ feature selection technique improves the accuracy by 3.5%. For the BCNET dataset, the proposed technique improves the F1 score by 1.8% for the Fisher feature selection technique. The experimental findings support the substantial improvement in performance from previous approaches by the new technique.
Ensure Security and Scalable Performance in Multiple Relay NetworksEditor IJCATR
A relay network is a broad class of network topology commonly used in networks, where the source and destination are
interconnected by means of a some nodes. In such a network the source and destination cannot transmit to each other directly because
the distance between the source and destination is greater than the transmission range of both of them, hence the demand for
intermediate node(s) to relay. The problem of detecting malicious relay nodes in single source, multi-relay networks has been studied
in the literature for different relaying schemes. Relay nodes in apply network coding while those in and follow the decode-and-forward
protocol. The authors consider a peer-to-peer (P2P) network in which peers receive and forward a linear combination of the exogenous
data packets. To check out the integrity of the received packets, a key signature vector is generated at the source node and broadcasted
to all nodes where it is used to check the integrity of the received packets. In and several information theoretic algorithms for
mitigating falsified data injection effects are proposed. The network modeling used in these works is composed of a single source,
multiple intermediate nodes which utilize network coding. We consider a multiple access relay network where multiple sources send
independent data to a single destination through multiple relays, which may interject falsified data into the network. To detect the
malevolent relays and dispose (efface) data from them, trace bits are embedded in the information data at each source node.
This document summarizes a research paper on dynamic resource allocation in wireless sensor networks. It proposes a load balancing mechanism that measures traffic load at each access point and shares the communication load among neighboring access points. It also proposes resource allocation for sensor networks that considers uplink and downlink channel information and network path/congestion data. Shortest path and routing algorithms are used to select optimal paths for sending data packets from source to destination nodes via intermediate nodes while dynamically allocating bandwidth. The mechanism aims to improve quality of service parameters like packet delivery, throughput, and efficiency of bandwidth allocation.
Transfer reliability and congestion control strategies in opportunistic netwo...IEEEFINALYEARPROJECTS
The document discusses transfer reliability and congestion control strategies in opportunistic networks. It begins by stating that opportunistic networks have unpredictable node contacts and rarely have complete end-to-end paths. It then discusses how modified TCP protocols are ineffective for these networks and they require different approaches than intermittently connected networks. The document surveys proposals for transfer reliability using hop-by-hop custody transfer and end-to-end receipts. It also categorizes storage congestion control based on single or multiple message copies. It identifies open research issues including replication management and drop policies for multiple copies.
A Secure Payment Scheme with Low Communication and Processing Overhead for Mu...Editor IJMTER
In this proposed work a trust-based routing protocol is developed to route messages through the
highly trusted nodes to minimize the probability of dropping the messages. Thus improve the network
performance in terms of throughput and packet delivery ratio. The proposed design contains a novel secure
reactive routing protocol for Mobile ad hoc networks (MANETs), called TRIUMF (Trust-Based Routing
Protocol with controlled degree of Selfishness for Securing MANET against Packet Dropping Attack). In the
proposed protocol trust among nodes is represented by trust value, which consists of cooperation score, direct
trust and indirect trust. The proposed trust routing allows controlled degree of selfishness to give an incentive to
the selfish nodes to declare its selfishness behavior to its neighbor nodes, which reduce the searching time of
misbehaving nodes to search for the malicious nodes only. In the proposed routing protocol two node-disjoint
routes between the source and destination nodes are selected based on their path trust values, one marked as
primary and the other as secondary. In this work both DLL-ACK and end- to-end TCP-ACK as monitoring
tools to monitor the behavior of routing path nodes: if the data packet successfully transmitted, then the path
nodes trust value are updated positively; otherwise, if a malicious behavior is detected then the path searching
tool starts to identify the malicious nodes and isolate them from the routing path and the network. Finally this
scheme reduces the searching time of malicious nodes, and the routing protocol avoids the isolated misbehaving
node from sharing in all future routes, which improves the overall network throughput.
Maximizing Efficiency Of multiple–Path Source Routing in Presence of JammerIOSR Journals
This paper explores maximizing the efficiency of multiple-path source routing in the presence of a jammer. It implements jamming-aware traffic allocation based on previous work, relaxing the assumption of in-network inference of variable correlations. The source node allocates traffic to paths based on estimated jamming statistics. Portfolio selection theory is used to optimize throughput. Simulation results using NS2 show the network is capable of jamming-aware allocation that increases throughput compared to ignoring jamming.
Mobile environment pretense a number of novel
theoretical and optimization issues such as position, operation
and following in that a lot of requests rely on them for
desirable information. The precedent works are sprinkled
across the entire network layer: from the medium of physical
to link layer to routing and then application layer. In this
invention, we present outline solutions in Medium Access
Control (MAC), data distribution, coverage resolve issues
under mobile ad-hoc network environment based on
congestion control technique using Transmission Control
Protocol (TCP). In mobile ad-hoc network issues can arise
such as link disconnections, channel contention and recurrent
path loss. To resolve this issue, we propose a Cross Layer
based Hybrid fuzzy ad-hoc rate based Congestion Control
(CLHCC) approach to maximize network performance. Based
on the destination report it regulates the speed of data flow to
control data loss by monitoring the present network status
and transmits this report to the source as advice. The source
adjusts the sending flow rate as per the advice. This is
monitored by channel usage, ultimate delay, short term
throughput.
Reliability Evaluation and Analysis of Mobile Ad Hoc Networks IJECEIAES
The paper addresses the reliability problem of mobile ad hoc networks under link and node failure model. Node reliability is calculated as a function of no. of neighbor nodes, packet success rate, and device type and packet size. The presence of a link between any node pair is binary and its reliability is computed considering the distance between nodes and signal-to-noise ratio (SNR). An efficient algorithm is proposed to analyze and calculate the reliability of mobile ad hoc networks considering multiple routes from source and destination nodes. The effect of different parameters on node reliability and link reliability are analyzed and discussed. The network is simulated and analyzed using INET frame work. Reliability of two distinct cases of this simulation is evaluated. The simulated results and discussions ensure that evaluation of the reliability of any mobile ad hoc networks can be done easily and in an efficient manner by the proposed method.
Link Disconnection Entropy Disorder in Mobile Adhoc Networkspaperpublications3
Abstract: In Mobile Ad-hoc Networks, nodes move freely causing an interruption in communications. This communication interruption can be accounted in a time lapse to an entropy to connection or disconnection; the combined entropy disorder of a node’s links describe how suitable a node is to communicate to neighbors. This entropy disorder is tightly coupled to mobility and communications factors such as node’s speed or data traffic saturation. In this paper, we analyze the relationship between speed and traffic saturation into a disorder in link entropy with a focus on disconnection, namely Link Disconnection Entropy Disorder (LDED). The findings indicate a high LDED value to nodes with high speed.
Application-Based QoS Evaluation of Heterogeneous Networks csandit
Heterogeneous wireless networks expand the network capacity and coverage by leveraging the
network architecture and resources in a dynamic fashion. However, the presence of different
communication technologies makes the Quality of Service (QoS) evaluation, management, and
monitoring of these networks very challenging. Each communication technology has its own
characteristics while the applications that utilize them have their specific QoS requirements.
Although, the communication technologies have different performance assessment parameters,
the applications using these radio access networks have the same QoS requirements. As a
result, it would be easier to evaluate the QoS of the access networks and the overall network
configuration depending on the performance of applications running on them. Using such
application-based QoS evaluation approach, the heterogeneous nature of the underlying
networks and the diversity of their traffic can be adequately taken into account. In this paper,
we propose an application-based QoS evaluation approach for heterogeneous networks.
Through simulation studies, we show that this assessment approach facilitates better QoS
management and monitoring of heterogeneous network configurations.
Survey paper on Evaluating Trust and Reputation Using Uncertain Reasoning in ...IJARIIE JOURNAL
This document discusses evaluating trust and reputation using uncertain reasoning in mobile ad hoc networks (MANETs). It first defines trust, reputation, and uncertain reasoning. It then discusses different routing protocols used in MANETs like AODV, OLSR, and DSR. It also discusses security attacks in MANETs and how trust and reputation models can be used to address these issues. Finally, it discusses probabilistic reasoning and Dempster-Shafer theory as ways to handle uncertainty in evaluating trust and reputation.
El documento presenta el programa de un simposio sobre fenomenología. El simposio incluye presentaciones sobre la técnica fenomenológica, el contexto histórico y las características de la fenomenología, así como las etapas del método fenomenológico y una sesión de interacción con un experto invitado. El objetivo es entender el mundo desde la perspectiva subjetiva de quien lo experimenta mediante la descripción y el análisis de casos vividos de manera directa.
Improved Cell Coverage in Hilly Areas using Cellular AntennasEswar Publications
This paper proposes an improved configuration of Cellular Antennas for terrains like hills where network coverage is poor and a number of black spots are very high. The proposed solution delivers efficient and much robust antenna structure which provides better network coverage by using 90-degree sector antennas. The radio spectrum of the 90-degree sector antenna is also shown to give the idea of cell coverage in order to build aseamless network in the region.This paper also proposes different channel allocation schemes that can be used with the proposed antenna configuration to deliver better network coverage and low call dropping probability.
This is achieved by analyzing the terrain of the region and also the cellular traffic in the region. In areas where network traffic is almost constant or have low population, strategies like fixed channel allocation can be used effectively and efficiently. While in the areas where traffic is unpredictable or is subject to regional festivals or tourism, channel strategies like dynamic channel allocation are very useful to fulfill the demand of the overall network. The simulations and validations for the proposed methodology are done using MATLAB.
NetSim (http://www.tetcos.com/) Best Network Simulator , provide wireless sensor network Based IEEE 802.15.4 Standard
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This certificate recognizes Maurits Tichelman for completing a course on June 8, 2016. The course was about Intel's 6th Generation Core vPro Platform and how it enables a new level of hardware-based security for businesses. Shawn Camp signed the certificate as Vice President and General Manager of Direct and Channel Sales.
The CDC recently released guidelines regarding the use of opioid medications in the treatment of chronic pain. The CDC recommends that clinicians should consider nonpharmacologic therapies like medical foods as a first line therapy to safely and effectively treat chronic pain.
The document describes the steps to construct a value stream map (VSM). It involves defining the current state map by gathering information on physical and information flows, cycle times, bottlenecks and defects. The future state map is then created by mapping an improved process and an implementation plan is made to achieve this. Key steps include identifying the product family, start/end points, gathering data on times, flows, inspections and linking this to create a current state map with production lead times. Future state suggestions aim to reduce changeovers and level production.
Lean Learning Activities: The Post Mortem ProcessTom Curtis
The document outlines the Post Mortem process for Lean Learning Activities using the six R's: Reset, Review, Resonance, Return, Resolve, Retain, Rework, Replace, and Retry. The process allows people to see how an activity was conducted, what needs improvement, and next steps to update the standard process.
Process Change: Communication & Training TipsTKMG, Inc.
Subscribe: ksmartin.com/subscribe
Recorded Webinar: http://bit.ly/1Gl23Hm
Rolling out process improvements is a common point of failure in organizations.
AN INTEGRATED SECURED ROUTING APPROACH FOR MANETSIRJET Journal
This document proposes an integrated routing approach for MANETs using machine learning algorithms. It uses a fuzzy clustering algorithm to select cluster heads based on trust values, providing multiple paths. An optimized route is then selected using Bacteria Foraging Optimization Algorithm (BFOA) to find the best path avoiding misbehaving nodes. The approach aims to provide secure, fast, and energy-efficient routing for MANETs challenged by frequent topology changes, limited power, and security threats.
Improving Network Security in MANETS using IEEACKijsrd.com
This document discusses improving network security in mobile ad hoc networks (MANETs) using an improved version of the EAACK intrusion detection system called IEEACK. IEEACK aims to address some of the weaknesses of EAACK related to link breakage, malicious sources, and partial packet dropping. The document describes the components of IEEACK, including ACK, S-ACK, MRA, digital signatures, and a new trust-based quality of service model. Simulation results show that IEEACK can prevent attacks from malicious nodes and improve security performance metrics like packet delivery ratio and detection of malicious nodes.
CHARACTERIZATION OF USER-PERCEIVED QUALITY OF SERVICE (QOS) IN MOBILE DEVICES...ijwmn
This paper presents a user-centric and application-specific QoS assessment methodology for cellular
communication networks. Specifically, it uses the Analytic Hierarchy Process (AHP) to evaluate QoS as a
multi-criteria decision problem that represents how well cellular networks’ data services are perceived
given particular sets of application classes and relative to other networks servicing in the same area. As
part of the methodology, drive testing is performed to collect objective measurements associated with
identified QoS criteria for data services. Once drive testing is performed and data collected, multiple
networks are compared to determine the network that provides higher QoS based on users’ perception of
quality. The selection of the best performing network is based on the output provided by the AHP
approach, which is used as unified measurement of the perceived QoS by users on different networks. In
order to determine application-specific priorities, the approach presented uses three different application
classes, including Emergency, Business, and Personal. For each class, the relative importance of each
quality evaluation criteria is adjusted in the AHP procedure to reflect the priorities of the services
expected. Through several case studies, the approach is proven successful in providing a way for
analyzing user-centric QoS for application-specific scenarios.
IRJET- Reliable Data Transmission in Wireless Network using Secure Trust ...IRJET Journal
This document proposes an Authenticated Anonymous Secure Routing (AASR) scheme to ensure reliable data transmission in wireless networks even against advanced attacks like false trust reporting or compromised node attacks. The AASR scheme improves routing performance by avoiding malicious nodes, isolating false trust information through a weight function, and considering both nodal and directional trust to select more reliable routing paths. Simulation results show AASR provides better performance than existing ATR and SPR schemes in dealing with Byzantine and compromised node attacks.
Improved Development of Energy Efficient Routing Algorithm for Privacy Preser...IRJET Journal
This document proposes an algorithm to improve energy efficiency and privacy preservation for the sink node in wireless sensor networks. The algorithm uses node clustering, where sensor nodes are grouped into clusters with a cluster head node. Data is routed from cluster members to their cluster head, and then from cluster heads to the sink node. The algorithm elects a subset of cluster heads to broadcast data, obscuring the location of the sink node and distributing energy usage across nodes. Simulations analyze how effectively this approach preserves sink node anonymity while limiting energy depletion across varying network conditions.
Machine Learning Based 5G Network Channel Quality PredictionIRJET Journal
The document discusses using machine learning techniques like CNN and SVM algorithms to predict channel quality in 5G networks. It aims to optimize channel quality indicator (CQI) reporting by reducing signaling overhead. The proposed system would apply these machine learning models to predict channel stability and decide whether reported CQI is necessary, controlling reporting frequency. Simulation results showed both CNN and SVM provide high prediction accuracy, with CNN outperforming SVM. Particle swarm optimization is also proposed to improve CNN training and recognition accuracy for CQI prediction. This could lead to more efficient CQI reporting over the long run.
APPLICATION-BASED QOS EVALUATION OF HETEROGENEOUS NETWORKS cscpconf
Heterogeneous wireless networks expand the network capacity and coverage by leveraging the network architecture and resources in a dynamic fashion. However, the presence of different communication technologies makes the Quality of Service (QoS) evaluation, management, and monitoring of these networks very challenging. Each communication technology has its own characteristics while the applications that utilize them have their specific QoS requirements. Although, the communication technologies have different performance assessment parameters, the applications using these radio access networks have the same QoS requirements. As a result, it would be easier to evaluate the QoS of the access networks and the overall network configuration depending on the performance of applications running on them. Using such application-based QoS evaluation approach, the heterogeneous nature of the underlying networks and the diversity of their traffic can be adequately taken into account. In this paper, we propose an application-based QoS evaluation approach for heterogeneous networks. Through simulation studies, we show that this assessment approach facilitates better QoS management and monitoring of heterogeneous network configurations.
33 9140 it immensely discriminate routing in wireless (edit lafi)IAESIJEECS
The document proposes the Immensely Discriminate Routing protocol for multi-hop routing in wireless networks. The protocol evaluates node distance, link quality, trust, and quality of service to determine the next hop. These parameters are used to calculate an efficient path through a matrix representation. The routing protocol operates in three stages - from the source node, to its adjacent nodes, and then the adjacent nodes' adjacencies. The protocol aims to provide efficient paths and improved throughput in wireless networks by selecting the next hop based on an evaluation of distance, link quality, trust, and quality of service parameters.
Wireless Sensor Network (WSN) is partially distributed autonomous sensors to monitor physical or environmental conditions such as temperature, pressure etc. and to cooperatively pass their data through the network to the central location. The technique referred to as multi-hop wireless communications is used by the WSN’s to communicate. Due to the limited processing power and the finite power accessible to each sensor nodes, the application of regular routing techniques is not recommended. Hence recent advances in wireless sensor networks have made the routing protocols more efficient. This paper surveys and compares the advanced routing protocols. The three main categories discussed here are flat based, hierarchical based and location based. The paper concludes with open research issues.
Energy- Aware QoS Based Routing Protocols for Heterogeneous WSNs: A Survey ...............................1
Sridevi S., Rumeniya G. and Usha M.
Optimization of Outsourcing ICT Projects in Public Organizations; Case Study: Public Center of Iranian
ICT Studies ................................................................................................................................................. 20
Majid Nili Ahmadabadi, Abbas Bagheri and Fariba Abolghasemi
An Optimized CBIR Using Particle Swarm Optimization Algorithm ......................................................... 40
Subhakala S., Bhuvana S. and Radhakrishnan R.
Study of Satisfaction Assessment Techniques for Textual Requirements .............................................. 56
K. S. Divya, R. Subha and Dr. S. Palaniswami
Survey of MAC Protocols for Heterogeneous Traffic in Wireless Sensor Networks ............................... 67
Sridevi S., Priyadharshini R. and Usha M.
Harnessing Social Media for Business Success. Case Study of Zimbabwe ............................................... 80
Musungwini Samuel, Zhou Tinashe Gwendolyn, Zhou Munyaradzi and Ruvinga Caroline
Quality Platforms for Innovation and Breakthrough................................................................................ 90
Dr. Hima Gupta
Development of Virtual Experiment on Waveform Conversion Using Virtual Intelligent SoftLab ...... 107
Bhaskar Y. Kathane
Link Prediction And Link Establishment Based On Network Nodes Life Time In Mo...inventionjournals
This document summarizes a research paper that proposes a new routing algorithm called the Link Prediction Routing Algorithm (LPRA) for mobile ad hoc networks. The LPRA aims to establish reliable links and perform persistent data forwarding based on predicting node and link lifetimes. It does so by selecting routes with the longest predicted lifetimes. The algorithm is evaluated through simulation and shown to improve performance metrics like throughput, delivery ratio, and delay compared to existing techniques. It aims to efficiently route data in unstable mobile ad hoc networks where topology frequently changes.
A mobile Ad-hoc network (MANET) is an impulsive network that can be recognized with no predetermined infrastructure. To achieve safe path selection cryptographic key exchange was implemented mostly in turn of huge computational cost. Confidence based coordination in MANET focuses on routing challenges created by selfish nodes, as energy utilization & time factor are key issues in this aspect. The present protocol is focused on fuzzy optimization-based node confidence estimation and path selection with minimum energy utilization. The node with maximum confidence value will give high priority to include in the path for transmission. In the implemented protocol to build a novel confidence-based model multidimensional factors like confidence value, link cost, degree of node and node energy are included as decision-making factors. The proposed protocol CLBNSRM estimates confidence level in four steps to decide a trustworthiness of neighboring node. To estimate the efficiency of the present confidence model various protocols are compared by using attributes like the number of nodes, node speed, malicious node variation, etc. Moreover, different parameters like Packet delivery ratio, Throughput, Residual energy, and Packet dropped are considered with these attribute variations. Experimental results indicate that PDR and Throughput increase although in presence of malicious nodes, along with the utilization of minimal energy. Statistical analysis is carried out for mathematical modeling. This analysis shows that a linear model of an implemented protocol is better than compared protocol with all the aspects.
IRJET- Aggregate Signature Scheme and Secured ID for Wireless Sensor Netw...IRJET Journal
This document proposes a cross-layer resource allocation scheme over wireless relay networks to guarantee quality of service (QoS) in terms of delay. The scheme aims to maximize network throughput subject to a given delay constraint, characterized by a QoS exponent θ. Dynamic resource allocation algorithms are developed for amplify-and-forward and decode-and-forward relay networks based on network channel state information and the QoS constraint. Simulations show the scheme efficiently supports diverse QoS requirements over wireless relay networks, and relay networks outperform direct transmissions under stringent delay constraints.
Data Rates Performance Analysis of Point to Multi-Point Wireless Link in Univ...IRJET Journal
This document analyzes the data rate performance of a point-to-multipoint wireless link in the University of Ilorin campus network. It describes using Ubiquiti Rocket M5 Titanium wireless devices located at the Network Operations Center to connect to five access points across campus. Monitoring software recorded transmission rates, reception rates, signal strength, noise, latency, and throughput between the access points. The analyses aimed to evaluate the impact of impairments like interference on network performance and compute regression coefficients to show how packet loss varies between access points.
Performance Evaluation and Comparison of On-Demand Routing Protocols for Ad H...Eswar Publications
Routing in mobile ad-hoc networks is an integral aspect of communication between devices. Routing is considered to
be a challenging task in MANETs due to the drastic and unpredictable changes in network topologies as a result of
the random and frequent movement of the nodes and due to the absence of any centralized control. Several routing protocols have been designed and developed to perform under various network environments. In this work a systematic simulation based performance study of the four prominent routing protocols: Ad hoc on Demand Multipath Routing Distance Vector (AOMDV), Dynamic Source Routing (DSR), Ad Hoc On Demand Distance Vector (AODV) and Temporarily Ordered Routing (TORA) protocols in the simulated networking environment under varying number of nodes in various scenarios is performed. These protocols use on-demand routing and have different protocol mechanisms leading to differences in performance. The performance is analyzed and evaluated based on end to end delay, packet delivery ratio, routing overheads and through-put done by varying network load, and the size of the network. Based on the observations, we make recommendations about the performance of the
protocols.
This document summarizes three trust-based security models for mobile ad hoc networks (MANETs):
1) The Secure MANET Routing Trust Intrigue (SMRTI) model calculates direct and recommended trust values to evaluate nodes, packets, and routes. It uses these evaluations to make security decisions.
2) The Maturity-Based model incorporates relationship maturity, where trust in long-term neighbors is given more weight. It uses a Recommendation Exchange Protocol for nodes to share recommendations.
3) The Trust Based Information Sharing (TRUISM) model defines properties like direct trusted neighbors and context-dependent trust. It calculates recommendation trust from opinions shared between neighbors.
ANALYTIC HIERARCHY PROCESS FOR QOS EVALUATION OF MOBILE DATA NETWORKSIJCNCJournal
This document describes using the Analytic Hierarchy Process (AHP) to evaluate the quality of service (QoS) provided by different 3G mobile data networks to determine which network provides the best QoS for web browsing applications. The AHP method builds a hierarchy with the goal of determining the best network at the top, criteria like latency, jitter, data loss and throughput in the middle, and alternative networks at the bottom. Pairwise comparisons are used to calculate weights for the criteria and alternatives. Measured data is collected for the criteria from drive testing of the networks. The weights are then combined to produce overall scores for each network, with the highest scoring network providing the best QoS. The study implements AHP
EVENT DRIVEN ROUTING PROTOCOLS FOR WIRELESS SENSOR NETWORK- A SURVEYijcsa
Advances in embedded systems have resulted in the development of wireless sensor networks, which not
only provide unique opportunities for monitoring but also controlling homes, cities and the environments.
Recent advancements in wireless sensor network have resulted into many new protocols some of them are
specifically designed for sensor network for detecting the event and routing the event related information to
the base station in efficient manner. This paper surveys recent event driven routing protocols for wireless
sensor network. We have compared various event driven routing protocols using different parameters like
Sink Centric, Node Centric, Reliability, Congestion control, Energy Efficiency, Loss reliability and loss
recovery. We have also described LEACH and MECN protocols but as they are not e
A Survey of Techniques Used To Detect Selfish Nodes in MANETijsrd.com
This document summarizes various techniques that have been used to detect selfish nodes in mobile ad hoc networks (MANETs). It begins with an introduction to MANETs and the problem of selfish nodes. It then describes several common approaches for detecting selfish nodes, including reputation-based schemes, credit-based schemes, and acknowledgement-based schemes. Specific techniques are discussed like watchdog, pathrater, CONFIDANT, CORE, OCEAN, 2ACK scheme, SORI, LARS, and others. Their advantages and disadvantages are summarized. Finally, the document proposes a combined approach using collaborative watchdog and credit risk to more quickly detect selfish nodes in a decentralized way while reducing overhead.
AN ALTERNATE APPROACH TO RESOURCE ALLOCATION STRATEGY USING NETWORK METRICSIN...ijgca
Monitoring in a grid environment involves the analysis of all resource metrics and network metrics. Monitoring the resource metrics helps the grid middle ware to decide which job to be
submitted to which resource. Decision for submitting a job will be better along with the consideration of the network metrics. Tuning of the network metrics is also made if the performance degrades.
Similar to A Study on Hardware and Software Link Quality Metrics for Wireless Multimedia Sensor Networks (20)
Content-Based Image Retrieval (CBIR) systems have been used for the searching of relevant images in various research areas. In CBIR systems features such as shape, texture and color are used. The extraction of features is the main step on which the retrieval results depend. Color features in CBIR are used as in the color histogram, color moments, conventional color correlogram and color histogram. Color space selection is used to represent the information of color of the pixels of the query image. The shape is the basic characteristic of segmented regions of an image. Different methods are introduced for better retrieval using different shape representation techniques; earlier the global shape representations were used but with time moved towards local shape representations. The local shape is more related to the expressing of result instead of the method. Local shape features may be derived from the texture properties and the color derivatives. Texture features have been used for images of documents, segmentation-based recognition,and satellite images. Texture features are used in different CBIR systems along with color, shape, geometrical structure and sift features.
This document discusses clickjacking attacks, which hijack users' clicks to perform unintended actions. It provides an overview of clickjacking, describes different types of attacks, and analyzes vulnerabilities that make websites susceptible. Experiments are conducted on a sample social networking site, applying various clickjacking techniques. Potential defenses are tested, including X-Frame-Options headers and frame busting code. A proposed solution detects transparent iframes to warn users and check for hidden mouse pointers to mitigate cursorjacking. Analysis of top Jammu and Kashmir websites found most were vulnerable, while browser behavior studies showed varying support for defenses.
Performance Analysis of Audio and Video Synchronization using Spreaded Code D...Eswar Publications
The audio and video synchronization plays an important role in speech recognition and multimedia communication. The audio-video sync is a quite significant problem in live video conferencing. It is due to use of various hardware components which introduces variable delay and software environments. The objective of the synchronization is used to preserve the temporal alignment between the audio and video signals. This paper proposes the audio-video synchronization using spreading codes delay measurement technique. The performance of the proposed method made on home database and achieves 99% synchronization efficiency. The audio-visual
signature technique provides a significant reduction in audio-video sync problems and the performance analysis of audio and video synchronization in an effective way. This paper also implements an audio- video synchronizer and analyses its performance in an efficient manner by synchronization efficiency, audio-video time drift and audio-video delay parameters. The simulation result is carried out using mat lab simulation tools and simulink. It is automatically estimating and correcting the timing relationship between the audio and video signals and maintaining the Quality of Service.
Due to the availability of complicated devices in industry, models for consumers at lower cost of resources are developed. Home Automation systems have been developed by several researchers. The limitations of home automation includes complexity in architecture, higher costs of the equipment, interface inflexibility. In this paper as we have proposed, the working protocol of PIC 16F72 technology is which is secure, cost efficient, flexible that leads to the development of efficient home automation systems. The system is operational to control various home appliances like fans, Bulbs, Tube light. The following paper describes about components used and working of all components connected. The home automation system makes use of Android app entitled “Home App” which gives
flexibility and easy to use GUI.
Semantically Enchanced Personalised Adaptive E-Learning for General and Dysle...Eswar Publications
E-learning plays an important role in providing required and well formed knowledge to a learner. The medium of e- learning has achieved advancement in various fields such as adaptive e-learning systems. The need for enhancing e-learning semantically can enhance the retrieval and adaptability of the learning curriculum. This paper provides a semantically enhanced module based e-learning for computer science programme on a learnercentric perspective. The learners are categorized based on their proficiency for providing personalized learning environment for users. Learning disorders on the platform of e-learning still require lots of research. Therefore, this paper also provides a personalized assessment theoretical model for alphabet learning with learning objects for
children’s who face dyslexia.
Agriculture plays an important role in the economy of our country. Over 58 percent of the rural households depend on the agriculture sector as their means of livelihood. Agriculture is one of the major contributors to Gross Domestic Product(GDP). Seeds are the soul of agriculture. This application helps in reducing the time for the researchers as well as farmers to know the seedling parameters. The application helps the farmers to know about the percentage of seedlings that will grow and it is very essential in estimating the yield of that particular crop. Manual calculation may lead to some error, to minimize that error, the developed app is used. The scientist and farmers require the app to know about the physiological seed quality parameters and to take decisions regarding their farming activities. In this article a desktop app for seed germination percentage and vigour index calculation are developed in PHP scripting language.
What happens when adaptive video streaming players compete in time-varying ba...Eswar Publications
Competition among adaptive video streaming players severely diminishes user-QoE. When players compete at a bottleneck link many do not obtain adequate resources. This imbalance eventually causes ill effects such as screen flickering and video stalling. There have been many attempts in recent years to overcome some of these problems. However, added to the competition at the bottleneck link there is also the possibility of varying network bandwidth which can make the situation even worse. This work focuses on such a situation. It evaluates current heuristic adaptive video players at a bottleneck link with time-varying bandwidth conditions. Experimental setup includes the TAPAS player and emulated network conditions. The results show PANDA outperforms FESTIVE, ELASTIC and the Conventional players.
WLI-FCM and Artificial Neural Network Based Cloud Intrusion Detection SystemEswar Publications
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Classification Algorithms with Attribute Selection: an evaluation study using...Eswar Publications
Attribute or feature selection plays an important role in the process of data mining. In general the data set contains more number of attributes. But in the process of effective classification not all attributes are relevant.
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Mining Frequent Patterns and Associations from the Smart meters using Bayesia...Eswar Publications
In today’s world migration of people from rural areas to urban areas is quite common. Health care services are one of the most challenging aspect that is must require to the people with abnormal health. Advancements in the technologies lead to build the smart homes, which contains various sensor or smart meter devices to automate the process of other electronic device. Additionally these smart meters can be able to capture the daily activities of the patients and also monitor the health conditions of the patients by mining the frequent patterns and
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Network as a Service Model in Cloud Authentication by HMAC AlgorithmEswar Publications
Resource pooling on internet-based accessing on use as pay environmental technology and ruled in IT field is the
cloud. Present, in every organization has trusted the web, however, the information must flow but not hold the
data. Therefore, all customers have to use the cloud. While the cloud progressing info by securing-protocols. Third
party observing and certain circumstances directly stale in flow and kept of packets in the virtual private cloud.
Global security statistics in the year 2017, hacking sensitive information in cloud approximately maybe 75.35%,
and the world security analyzer said this calculation maybe reached to 100%. For this cause, this proposed
research work concentrates on Authentication-Message-Digest-Key with authentication in routing the Network as
a Service of packets in OSPF (Open Shortest Path First) implementing Cloud with GNS3 has tested them to
securing from attackers.
Microstrip patch antennas are recently used in wireless detection applications due to their low power consumption, low cost, versatility, field excitation, ease of fabrication etc. The microstrip patch antennas are also called as printed antennas which is suffer with an array elements of antenna and narrow bandwidth. To overcome the above drawbacks, Flame Retardant Material is used as the substrate. Rectangular shape of microstrip patch antenna with FR4 material as the substrate which is more suitable for the explosive detection applications. The proposed printed antenna was designed with the dimension of 60 x 60 mm2. FR-4 material has a dielectric constant value of 4.3 with thickness 1.56 mm, length and width 60 mm and 60 mm respectively. One side of the substrate contains the ground plane of dimensions 60 x60 mm2 made of copper and the other side of the substrate contains the patch which have dimensions 34 x 29 mm2 and thickness 0.03mm which is also made of copper. RMPA without slot, Vertical slot RMPA, Double horizontal slot RMPA and Centre slot RMPA structures were
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Ivanti’s Patch Tuesday breakdown goes beyond patching your applications and brings you the intelligence and guidance needed to prioritize where to focus your attention first. Catch early analysis on our Ivanti blog, then join industry expert Chris Goettl for the Patch Tuesday Webinar Event. There we’ll do a deep dive into each of the bulletins and give guidance on the risks associated with the newly-identified vulnerabilities.
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A Comprehensive Guide to DeFi Development Services in 2024Intelisync
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In the rapidly evolving landscape of technologies, XML continues to play a vital role in structuring, storing, and transporting data across diverse systems. The recent advancements in artificial intelligence (AI) present new methodologies for enhancing XML development workflows, introducing efficiency, automation, and intelligent capabilities. This presentation will outline the scope and perspective of utilizing AI in XML development. The potential benefits and the possible pitfalls will be highlighted, providing a balanced view of the subject.
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DLAU und die Lizenzen nach dem CCB- und CCX-Modell sind für viele in der HCL-Community seit letztem Jahr ein heißes Thema. Als Notes- oder Domino-Kunde haben Sie vielleicht mit unerwartet hohen Benutzerzahlen und Lizenzgebühren zu kämpfen. Sie fragen sich vielleicht, wie diese neue Art der Lizenzierung funktioniert und welchen Nutzen sie Ihnen bringt. Vor allem wollen Sie sicherlich Ihr Budget einhalten und Kosten sparen, wo immer möglich. Das verstehen wir und wir möchten Ihnen dabei helfen!
Wir erklären Ihnen, wie Sie häufige Konfigurationsprobleme lösen können, die dazu führen können, dass mehr Benutzer gezählt werden als nötig, und wie Sie überflüssige oder ungenutzte Konten identifizieren und entfernen können, um Geld zu sparen. Es gibt auch einige Ansätze, die zu unnötigen Ausgaben führen können, z. B. wenn ein Personendokument anstelle eines Mail-Ins für geteilte Mailboxen verwendet wird. Wir zeigen Ihnen solche Fälle und deren Lösungen. Und natürlich erklären wir Ihnen das neue Lizenzmodell.
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HCL Notes und Domino Lizenzkostenreduzierung in der Welt von DLAU
A Study on Hardware and Software Link Quality Metrics for Wireless Multimedia Sensor Networks
1. Int. J. Advanced Networking and Applications
Volume: 08 Issue: 03 Pages: 3103-3109 (2016) ISSN: 0975-0290
3103
A Study on Hardware and Software Link Quality
Metrics for Wireless Multimedia Sensor Networks
Mrs. G. Kirubasri 1
, Dr .N. Uma Maheswari 2
1
Assistant Professor, 2
Professor
Department of CSE,
P.S.N.A. College of Engineering and Technology,
Dindigul,India.
1
kiruba.me2010@gmail.com
2
numamahi@gmail.com
-------------------------------------------------------------------ABSTRACT---------------------------------------------------------------
Due to the lack of accurate evaluation of the transmission characteristics of the wireless communication links,
routing algorithms in wireless sensor networks may result in poor network performance. In order to avoid
sending packets over the unstable link, routing protocol has to rely on noble metrics to choose better routing path.
Better estimation of link reliability between neighboring nodes could permit the selection of a more reliable route.
Since the routing metrics play an important role as they have a direct impact on the efficiency and robustness of
routing protocols. Different routing metrics will provide different performances to routing protocols when used to
compute weight of paths. This paper presents a study on various hardware and software link quality metrics that
help network protocol designers can choose an efficient Link Quality Estimator to develop reliable routing
techniques for WMSNs. Additionally a classification tree of different routing metrics is presented which helps in
understanding the strengths and weaknesses of these LQ metrics, thus enabling the designer of the routing
protocol to make an informed choice.
Keywords— Link Quality, routing protocol, sensor networks, need for link quality analysis, LQI, PRR, RNP.
--------------------------------------------------------------------------------------------------------------------------------------------------
Date of Submission: Dec 12, 2016 Date of Acceptance: Dec 23, 2016
--------------------------------------------------------------------------------------------------------------------------------------------------
I. INTRODUCTION
In Wireless Sensor Networks (WSNs), link quality
estimation is more challenging than in the other traditional
wireless mesh and ad-hoc networks[1], because sensor
nodes are densely deployed and basically use low-power
radios. It has been experimentally shown that low-power
radios are more prone to noise, interference, and multipath
distortion [2]. The propagation of wireless signals with
low-power radios is affected by several factors that
contribute to the degradation of its quality. Consequently,
radio links in WSNs are often unpredictable. In fact, their
quality fluctuates over time and space. As a result,
communication links in WSNs exhibit more unreliability.
Generally Routing in networks addresses the problem
of finding efficient paths for data forwarding between
source and destination nodes. Most of the routing protocols
typically rely on metrics such as hop-count or end-to-end
delay [3], which do not explicitly reflect link quality. This
can result in poor path selection, since the routing protocol
is not aware of reliability of the links. These conditions can
make communication inefficient, resulting in
communication loss and frequent packet retransmissions.
In addition to using the traditional metrics, routing
techniques can infer more knowledge on the forwarding
path with the help of Link quality estimation, is the process
through which many routing techniques designed for
wireless networks can be able to know the quality of the
link after analysing its dynamic behaviour so as to select
the suitable path for packet the help of t transmission. Now
a day many sophisticated routing protocols aim to
overcome link unreliability in order to efficiently maintain
network connectivity. With the aim of achieving this, they
over sees the link quality estimation (LQE) as a support
mechanism to select the most stable routes for data. Stable
routes are built by selecting links with the highest quality
and discarding those of bad quality. Building such routes
will definitely improve the network throughput and
maximize its lifetime.
The link quality estimation process comprises of link
monitoring, link measurements, and metric evaluation.
Link monitoring involves three kinds .they are (i) active
link monitoring,(ii.) passive link monitoring, and (iii.)
hybrid link monitoring. Passive monitoring involves
evaluating data from received packets during
communication while active monitoring entails sending
probe packets and evaluating data from response packets.
Passive link monitoring has been widely used in WSNs
due to its energy-efficiency compared to active link
monitoring. The use of a hybrid mechanism combining
both active and passive monitoring may yield an efficient
balance between up-to-date link measurements and energy-
efficiency [4]. In general, the quality of a link is estimated
as a proportion of successfully received packets. Hence,
the goodness of a link is linear to the proportion of
2. Int. J. Advanced Networking and Applications
Volume: 08 Issue: 03 Pages: 3103-3109 (2016) ISSN: 0975-0290
3104
received packets. Thus, a generic observation is that each
link may belong to one of the following zones: high link
quality, transitional (’gray zones’) for intermediate link
quality, and low link quality.
Efficient link quality estimation has several
requirements such as Energy efficiency, Accuracy,
Reactivity and Stability etc. in order to minimize high
communication overhead, to correctly characterize the link
state, to quickly react to persistent changes in link quality
and to tolerate transient (short-term) variations in link
quality.
II. CATEGORY OF LINKQUALITY
ESTIMATORS
Link quality estimators in wireless sensor networks
can roughly be classified in two categories such as
hardware-based estimators and software-based estimators.
Hardware-based estimators include Link Quality Indicator
(LQI) Received Signal Strength Indicator (RSSI) and
Signal to- Noise Ratio (SNR). These estimators are
directly obtained from the hardware for example CC2420
radio transceiver [5]. Their advantage is that they do not
require any computation overhead as they are built-in
directly on the hardware. However, as it was observed and
reported in pervious experimental studies, hardware-based
estimators do not provide accurate estimate. These metrics
are measured based on 8 symbols of a received packet and
not the whole packet. Second, these metrics are only
measured for successfully received packets. Therefore,
when a radio link suffers from excessive packet loss, they
could overestimate the transmission performance by not
considering the information of lost packets. They are also
dependant on the transceiver model, as LQI, for instance,
might not be available on all radio transceivers. Figure 1
represents the association different link quality metrics
based on their estimation type.
On the other hand Software based LQEs are
computed by the number of received and sent packets and
different strategies are adopted to calculate these software
based link quality estimators. Some software based link
quality estimators are calculated at the sender node side,
while others are calculated at the receiver node side [6].
These estimators enable to count or approximate either the
reception rate or the average number of packet
transmissions/re-transmissions, required before its
successful reception. Based on that Software-based LQEs
can be classified into three categories, such as (i.) PRR-
based: either count or approximate the PRR, (ii.) RNP-
based: either count or approximate the RNP (Required
number of Packet retransmissions), and (iii.) Score-based:
provide a score identifying the link quality. Some of the
software LQEs are Packet Reception Rate (PRR),
Acquitted Reception Rate (ARR) count the reception rate
and ETX - based metrics will account for expected number
of retransmission for the successful reception of data.
These link quality estimators are simple, yet they have
been widely used in routing protocols. The main difference
between hardware and software based estimators is the fact
that hardware based estimators only rely on received
packet information, they do not account for packet loss.
Software based estimators account for packet loss by
incorporating data collected from the data link layer, such
as packet retransmissions.
Despite the fact that hardware metrics provide a fast
and inexpensive way to classify links as either good or
bad, they are incapable of providing a fine grain estimation
of link quality. The above limitations of hardware-based
LQEs do not mean that this category of LQEs is not useful.
In fact, each of these LQEs provides particular information
on the link state, but none of them is able to provide a
holistic characterization of the link quality. Currently,
there is a growing awareness that the combination of
hardware metrics with software metrics can improve the
accuracy of the link quality estimation.
III. NEED FOR LINK QUALITY
ESTIMATION
Link quality estimation is a fundamental problem in
wireless networks, and in particular sensor and mobile ad
hoc networks, due to the fact that the accuracy of link
quality estimation has a fundamental impact on the
efficiency of networking protocols. In Wireless SENSOR
Networks (WSN) routes towards sinks are evaluated using
link cost metrics also known as link estimators.
Figure 1: Organization of different LQEs
Link estimators can play an important role in a route
algorithm to choose the “best” route towards the sink using
different properties of the links. A link estimator chooses
one of the neighbouring nodes as a parent node and
transmits data towards the sink using that node. The node
that a link estimator chooses as a parent is considered as
the “best” in terms of a cost function. Poor link estimation
may lead to a less stable network with higher packet loss
and/or higher delays. Ideally, a routing protocol for a
wireless multihop network should favour the use of good
3. Int. J. Advanced Networking and Applications
Volume: 08 Issue: 03 Pages: 3103-3109 (2016) ISSN: 0975-0290
3105
quality links.The problem is particularly critical in
multihop routing when link-quality-aware metrics [7] (e.g.,
expected transmission count (ETX), expected transmission
time are used to select the best neighbour to relay a
message. The availability of robust link quality estimates is
even more critical when routing needs to support quality-
of-service provisioning (e.g. in the case of voice or video
data transmissions). Other important applications that can
benefit from the availability of accurate link estimation
models include, among others: sensor placement, topology
control, and load-balancing, relay node placement,
network failure diagnosis, coordination in sensor-actor
networks. Accurate and reliable link quality estimation is a
challenging task in wireless networks. In fact, the effective
quality of Link assessment is required for a better
comprehension of the environments we cope with. More
specifically, a good perception on the link behaviour helps
to design robust link quality estimators (LQEs). In fact, a
good LQE for routing has to guarantee low energy
consumption, stable topology, a high throughput, a low
end-to-end delay, reliable paths when retransmissions are
present, and low churn (neighbour changes). On the other
hand, it should be reactive, able to predict short and long
term link fluctuations, stable in time, to accurately
discriminate link quality, should rely on simple
computation (light memory footprint), or to have accurate
predefined thresholds to Discriminate unreliable
neighbours (blacklist mechanism).
To overcome the energy waste, LQEs should
properly foresee the quality of the link over few samples.
Since a wrong decision leads to packet loss and neighbour
changes, which are costly. More exactly, when routing
relies on bad links, retransmissions at the MAC layer
increase, which causes energy waste. If the metric fails
choosing an unreliable neighbour, interferences through
concurrent transmissions are introduced. Interference that
affects the quality of neighbouring links. Therefore, the
main requirements related to forwarding data over
dynamic wireless links are designing good link estimators.
IV. HARDWARE METRICS
Many radio chips that implement proprietary radio
technologies provide the received signal strength indicator
(RSSI), which is the strength of a received radiofrequency
(RF) signal, researchers considered the use of PHY
parameters from off-the-shelf radio hardware [8].
Furthermore, IEEE 802.15.4-compliant radio chips, like
the widely used Chipcon CC2420, also offer the LQI. As
defined by the standard, measurement of the LQI may be
implemented by means of receiver energy detection, signal
to-noise ratio estimation, or a combination of these
methods.
1. Received Signal Strength Indicator (RSSI)
In the newer radios such as CC2420, the RSSI is an
8-bit integer value. It is read from the RSSI register (in
case of the signal absence, the value indicates the noise).
RSSI for CC2420 radio chip is computed over the eight
symbol period (128μs) using equation (1).
� [ ] = � � � + � − − −
where The RSSI VAL is a 12 bit register and the RSSI
OFFSET is equal to -45dBm. RSSI ranges from -28dBm to
-127dBm. RSSI can provide a quick and accurate estimate
of whether a link is of very good quality. The empirical
studies proved the existence of a RSSI value (-87 dBm)
above which the PRR is consistently high (99%) i.e.,
belong to the connected region. Below this threshold, a
shift in the RSSI as small as 2 dBm can change a good link
to a bad one and vice versa, which means that the link is in
the transitional or disconnected region. Second, RSSI is
very stable (standard deviation less than 1 dBm) over a
short time span (2 s), thereby a single RSSI reading (over a
packet reception) is sufficient to determine if the link is in
the transitional region or not.
2. Signal to- Noise Ratio (SNR)
Another measure extensively used to quantify link
behaviour is SNR that denotes the strength of the signal. It
is defined as the ratio of the received signal strength and
the strength of the background noise. To estimate SNR, the
receiver records at first the RSSI of the received packet,
and then it has to measure the background noise. RSSI of a
signal is defined as:
RSSI [dBm] = 10log10 (Power received packet +
Background noise),
RSSI of the ambient noise is estimated as 10log10
(Background noise):
SNR [dBm] = RSSI [dBm] − Background noise
[dBm] (2.9)
3. Link Quality Indicator (LQI)
The Link Quality Indicator (LQI) is a metric that
estimates the current quality of the received information.
For CC1101, LQI gives an estimate of how easily a
received signal can be demodulated by accumulating the
magnitude of the error between ideal constellations and the
received signal over the 64 symbols immediately following
the sync word [76] .It ranges between [0...127]. A low
value indicates a good link quality. Thus, its values depend
on the used modulation (2-SK/GFSK/MSK/OOK).Many
Simulation results show that our adaptation of the LQI
metric is among the best route selection criteria regardless
of the performance criterion under consideration, and that
the load balancing significantly improves the routing
efficiency by lengthening the network lifetime while
minimizing packet losses[9],[10][11]. The CC2420 chip
provides a correlation value that is based on the first eight
symbols of the incoming packet. This correlation value is
in the range of 50 to 110, where 50 correspond to the
lowest quality frames detectable by the chip and 110
4. Int. J. Advanced Networking and Applications
Volume: 08 Issue: 03 Pages: 3103-3109 (2016) ISSN: 0975-0290
3106
indicates a maximum quality frame. According to the
standard, the LQI value is represented by one byte. For this
reason, Chipcon suggested the use of a linear conversion
of the correlation values into a range of 0 to 255, using
empirical methods based on Packet Error Rate (PER)
measurements. In addition, the LQI value may be obtained
by combining the correlation and RSSI values. However,
the LQI values have been assumed to be the correlation
values in the relevant literature, without the range
conversion [12][13].One of the first attempts at a link
quality estimator for a routing protocol based on the LQI
was MultiHopLQI [6], which was actually an evolution of
the aforementioned many-to-one scheme proposed in [5].
A path cost metric is computed as the sum of the link costs
of the path. The cost of a link is inversely proportional to
the LQI. It might be reasonable to use a single RSSI or
LQI reading to decide if the link is of high quality or not.
Such decision is based on RSSI and LQI thresholds,
beyond which a link can maintain high quality, e.g., a PRR
of at least 95% [18]. Importantly, these thresholds depend
on the environment characteristics. For example, Lin et al.
[2006] found that RSSI threshold is around -90 dBm on a
grass field, -91 dBm on a parking lot, and -89 dBm in a
corridor. For LQI and RSSI values below these thresholds,
neither of these metrics can be used to differentiate links
clearly. Nevertheless, an average LQI, with the convenient
averaging window, allows a more accurate classification of
intermediate links [23].
V. SOFTWARE-BASED LQES
Software-based LQEs can be classified into three
categories, such as (i.) PRR-based (ii.) RNP-based and
(iii.) Score-based.
1. PRR BASED
1.1. Packet Reception Rate (PRR)
PRR is a receiver side estimator that is simple to
measure and was widely used in routing protocols [6]. This
metric is computed at the receiver for each window of w
received packets, as follows:
=
�
− −
The number of lost packets is determined using the
sequence number of packets. The PRR is based on passive
monitoring, which means that useful statistical data is
collected from received/sent data packets over that link.
Further, it was often used as an unbiased metric to evaluate
the accuracy of hardware-based estimators. In fact, a
hardware-based estimator that correlates with PRR is
considered as a good metric [14]. The main objective of
approximating the PRR is to provide more efficient link
quality estimates than the current PRR of a link. The
efficiency of PRR depends on the adjustment of the time
window size. Links with very high or very low PRRs,
accurate link quality estimation can be achieved within
narrow time windows. On the other hand, links with
medium PRRs need much larger time windows to
converge to accurate link quality estimation.
1.2. The Window Mean with Exponentially Weighted
Moving Average (WMEWMA)
A filter based link quality estimator which uses the
EWMA filter as main estimation technique, based on link
measurements, the PRR is computed and then smoothed to
the previously computed PRR using EWMA filter which
provides more stable but sufficiently agile estimation
compared to PRR It is a receiver-side LQE based on
passive monitoring. It smoothes PRR estimates using the
EWMA filter, To assess the performance of WMEWMA,
A set of LQEs that approximate the PRR using filtering
techniques other than EWMA. Then, they compared
WMEWMA to these filter-based LQEs, in terms of (i.)
reactivity assessed by the settling time and the crossing
time, (ii.) accuracy evaluated by the mean square error,
(iii.) stability assessed by the coefficient of variation, and
(iv.) efficiency assessed by the memory footprint and
computation complexity. WMEWMA was found to
outperform the other filter-based LQEs. The work by Woo
and Culler [24],[25] laid the foundation for subsequent
work on filter-based LQE, although their solution required
a more thorough assessment, e.g., based on real-world data
traces instead of synthetic ones (i.e., generated
analytically). The Kalman filter based link quality
estimator (KLE) was proposed [25] to overcome the poor
reactivity of average-based LQEs, including PRR.
2. RNP BASED
2.1. Requested Number of Packets (RNP )
It counts the average number of packet
transmissions/re-transmissions required before a successful
reception. It is introduced in [6], follow passive
monitoring, this metric is evaluated at the sender side for
each transmitted and re-transmitted packets as follows:
=
� & �
� �
− − − −
where the first packet transmission is excluded. Note that
the number of successfully received packets is determined
by the sender as the number of acknowledged packets.
RNP is more reactive than PRR but it can underestimate
link quality[15][16]. In fact, RNP is a sender side LQE,
i.e., it is computed based on transmitted packets.
Consequently, RNP is able to provide link quality
estimates as long as there is traffic generated from the
sender. Various authors argue that RNP is better than PRR
for characterizing the link quality because PRR provides a
coarse-grain estimation of the link quality since it does not
take into account the underlying distribution of losses, in
contrast to RNP. On the other hand, RNP can be computed
even if no packet is received. However, RNP can
underestimate link quality in particular situations, as
sometimes packets are retransmitted many times before
being successfully received. This situation yields to good
PRR but bad RNP.
On the other hand, RNP can be computed even if no
packet is received. RNP is not aware of the link asymmetry
5. Int. J. Advanced Networking and Applications
Volume: 08 Issue: 03 Pages: 3103-3109 (2016) ISSN: 0975-0290
3107
in the sense that they provide an estimate of the quality of
the unidirectional link from the sender to the receiver.
However, RNP can underestimate link quality in particular
situations, as sometimes packets are retransmitted many
times before being successfully received. This situation
yields to good PRR but bad RNP. RNP has the
disadvantage of being very unstable and cannot reliably
estimate the link packet delivery, mainly due to link
asymmetry
2.2. The Expected Transmission Count (ETX)
A receiver-side estimator that uses active monitoring.
It measures link quality by estimating the number of
transmissions and retransmissions needed to send a data
packet over a link. ETX is the inverse of the product of the
forward delivery ratio and the backward delivery ratio,
which takes into account link asymmetry.
To get the ETX value, every node broadcasts a probe
packet periodically to neighbouring nodes. The formula to
calculate ETX is as given as follows:
� =
−
− − − − −
Where, the forward delivery ratio, df, denotes the
probability that a packet will be successfully delivered in
the forward direction, and the reverse delivery ratio dr
denotes the probability of receiving the corresponding
acknowledgement packet. Therefore, ETX involves the
delivery ratio and the number of transmissions in both
directions over a link. Since the two probabilities are
independent, df × dr can be understood as the expected
probability of a successful transmission, which includes
acknowledgement. df × dr is also equal to (1- Pf ) ×(1- Pr),
where Pf and Pr are the forward and reverse packet loss
ratios. Experiments proved that routing protocols based on
the ETX metric provide high-throughput routes on
multihop wireless networks. However, [17] found that
ETX based on passive monitoring fails in overloaded
(congested) networks, since a large number of nodes are
not able to compute the ETX because they do not receive
packets.
The main disadvantages of ETX lie in the way it
broadcasts small probe packets to detect data delivery ratio,
and that probe packets are sent at a lower data rate. This
estimation may not reflect the real packet loss ratio,
because actual packets are usually larger and sent at higher
data rates. Additionally, ETX does not take link data rates
into account. The same packet loss ratio may be associated
with different data rates and link delays. For this reason,
ETX is more suitable for single-rate networks.
2.3. Four bit
Four-bit is not only a metric for link quality
estimation [Fonseca et al. 2007]. It is designed to be used
by routing protocols and provides four bits of information,
compiled from different layers: the white bit is from the
physical layer and allows to quickly identifying good
quality links, based on one packet reading. The ack bit is
from the link layer and indicates whether an
acknowledgment is received for a sent packet. The pin bit
and the compare bit are from the network layer and are
used for the neighbour table replacement policy. Four-bit
assesses link quality as an approximation of the packet
retransmissions count by combining two metrics (RNP and
WMEWMA) through the EWMA filter. The first metric is
RNP, computed based on the transmitted data packets and
it assesses the quality of the forward link. The second
metric is the inverse of WMEWMA minus 1. It is
computed based on received beacons and it assesses the
quality of the backward link. Four-bit is then both a
sender- and received-side LQE and it takes into account
link asymmetry. It is a hybrid estimator as it uses both
passive and active (beacons traffic) monitoring. [18] found
that CTP based on four-bit provides better performance
(e.g., packet delivery) than the original version of CTP and
Multi Hop. During active monitoring, nodes periodically
broadcast probe packets. Based on wa received probe
packets, the sender computes the WMEWMA estimate and
derives an approximation of the RNP, denoted as
estETXdown, as follows:
estETXdown =
1
WMEWMA
- ----
This metric estimates the quality of the unidirectional link
from the receiver to the sender based on active monitoring.
During passive monitoring, the sender computes RNP
based on number of transmitted/re-transmitted data packets
to the receiver.Then, it uses EWMA filter to smooth RNP
into estETXup, expressed as follows:
� = � × � + − � × − − −
In Eq. (6), the metric estETXup estimates the quality of the
unidirectional link from the sender to the receiver based on
passive monitoring. Thus, the four-bit estimator combines
both estETXup and estETXdown metrics via the EWMA
filter, in order to obtain an estimate of the bidirectional
link expressed as follows:
� = � × � + − � × � − − −
where estETX corresponds to estETXup or estETXdown :
At wa received probe packets, the sender drives the four-
bit estimate according to Eq. (7) by replacing estETX by
estETXdown . At wp transmitted/re-transmitted data
packets, the sender drives the four-bit estimate according
to Eq. (7) by replacing estETX by estETXup.
2.4. L-NT and L-ETX
The L-NT and L-ETX is two sender-side LQEs that
approximate the RNP. They are referred as data-driven
LQEs because they are based on feedback from unicast
data packets. L-NT counts the number of transmissions to
successfully deliver a packet then applies the EWMA
filter. On the other hand, L-ETX first computes the ratio of
the number of acknowledged packets to the total number
of transmitted packets based on a certain estimation
window. Then, it applies the EWMA filter and inverts the
result. Through mathematical analysis and experimental
measurements, L-ETX is more accurate in estimating ETX
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Volume: 08 Issue: 03 Pages: 3103-3109 (2016) ISSN: 0975-0290
3108
than L-NT. It is also more stable. However, this result does
not mean that L-ETX is accurate at estimating link quality
because ETX is not a reference/objective metric. The
authors also showed through an experimental study that L-
NT, when used as a routing metric, achieves better routing
performance than L-ETX, namely a higher data delivery
ratio and energy efficiency. This result might be more
convincing than the first as it indeed shows that L-ETX is
an accurate LQE. Such routing performances can be
explained by the fact that L-ETX allows to select stable
routes with high quality links.
3. SCORE BASED
Some LQEs provide a link estimate that does not
refer to physical phenomena (like packet reception or
packet retransmission); rather, they provide a score or a
label that is defined within a certain range. In the
following, we present an overview on score-based LQEs
such as WRE, F-LQE
3.1. Fuzzy- Link Quality Estimator (F-LQE)
The Fuzzy Link Quality Estimator (F-LQE) is a
receiver-side estimator. In contrast to existing LQEs,
which only assess one single link property thus providing a
partial view of the link, F-LQE estimates link quality on
the basis of four link properties in order to provide a
holistic characterization of the link, namely Smoothed
Packet Reception Ratio (SPRR), link stability factor (SF),
link Asymmetry Level (ASL), and channel Average-
Signal-to-Noise Ratio (ASNR).To validate their estimator,
The statistical properties of F-LQE, independently of
higher layer protocols [4] such as MAC collisions and
routing. These statistical properties impact its
performance, in terms of reliability and stability. The
performance of F-LQE was compared in terms of
reliability and stability with 5 existing LQEs: PRR,
WMEWMA, ETX, RNP and Four-bit. It was found that F-
LQE outperforms all these LQEs because they are only
able to assess a single link property[20][21][22]. However,
F-LQE might involve higher memory footprint and
computation complexity as it combines four different
metrics capturing four different link properties. The natural
language of Fuzzy Logic, and combined into a Fuzzy rule
to express link quality. For a particular link, the fuzzy
logic interpretation of the rule gives an estimation of its
quality as a membership score in the fuzzy subset of good
quality links. Scores near 1/0 are synonym of good/poor
quality links. Membership scores are smoothed using the
EWMA filter to provide stable link quality estimates.
3.2. The Weighted Regression Estimator (WRE)
It is proposed in [24] and argued that the received
signal strength is correlated with distance. This
observation was generalized to the fact that a node can
determine the quality of the link to its neighbour giving the
location of this neighbour. Hence, WRE derives a complex
regression function based on an input vector that contains a
set of nodes locations together with their links quality
known in advance. This function is continuously refined
and updated by the knowledge of a new input, i.e., node
location and the corresponding link quality. Once derived,
this function returns an estimation of the link quality
giving the neighbour location[23]. The performance of
WRE is evaluated by comparing it to WMEWMA using
the same evaluation methodology as that of used in [25],
where PRR is considered as the objective metric. Existing
work found that WRE is more accurate than WMEWMA.
However, we believe that the introduced estimator is
complex and involves computation overhead and high
memory storage (due to regression weights determination).
Moreover, WRE assumes that link quality is correlated
with distance, which is not always true, as proved by
several empirical studies on low-power links
[24],[25],[26].
VI. CONCLUSION AND FUTURE WORK
Link quality estimation has been attracting a lot of
attention in the WSN community as it emerges as a
fundamental building block for several protocols such as
MAC, routing, mobility management, and localization.
This paper fills a gap by presenting the first attempt to
survey and understand the fundamental concepts related to
link quality estimation in WSNs. Further it was devoted to
link quality estimation, where we described the main
related aspects and provided a first taxonomy of LQEs
[26]. This part demonstrates that research on link quality
estimation is challenging and far from being completed.
Efficient link quality estimation that provides a fine grain
classification of links, especially intermediate links, should
be based on several link quality metrics. In this paper, we
proposed a comparative study of a set of the well-known
hardware and software based link quality estimators,
namely LQI, RSSI, SNR, PRR, RNP, WMEWMA, ETX
and Four-Bit etc. In future works one of the challenges is
the design of estimators that make a good balance between
stability and accuracy. Another challenge is design of
estimators that take into account several parameters which
should address the shortcomings of existing estimators.
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