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Sensor node failure detection using round trip path and delay

Sensor node failure detection using round trip path and delay

2011) was not widely used as it consumed more energy because of the redundancy. The network speed and the number of correct results throughout the lifespan of the network decrease on using this method. Ravindra N Duche and Sarwade, (2012) proposed method is used to detect the sensor node failure or malfunctioning. This method used confidence factors (Duche, 2012) to detect faulty node. Confidence factor of round trip path in network is evaluated by using the round trip delay (RTD) time. This method detects the failure of sensor node present in symmetrical network conditions. The confidence factor of round trip path is calculated based on threshold and instantaneous round trip delay time. It were stored in lookup table and then by analyzing the status of confidence factor of all paths from the look-up table, failed or malfunctioning sensor node was detected easily. This method was able to detect only one faulty node present in any path in an easy and efficient way. That was the drawback of this method. Therefore this method has to be modified to optimize the number of round trip paths and the number of sensor nodes in the corresponding paths. NevidhithaBonnita et al. (2015) proposed discrete clustering approach (NevidhithaBonnita et al., 2015) to detect the faulty sensor node. Detection of faulty node was based on discrete RTPs. RTD times of discrete RTPs were compared with threshold time to determine failed sensor node. Software tool NS2 was used to implement RTDT protocol. Faulty sensor node was detected by simulating circular topology WSNs with RTDT protocol. Analysis time to detect faulty node was very much optimized by using the discrete RTPs. The sensor node more than threshold value was detected the failure sensor node. Senor node was detected as faulty node If calculated time is higher than the threshold value. Detection time depends upon the numbers of RTPs and RTD time. It detects the faulty node but it does not address recovering process of failure node.
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Failure detection of sensor nodes based on Round Trip Delay and Paths in Wireless Sensor Networks

Failure detection of sensor nodes based on Round Trip Delay and Paths in Wireless Sensor Networks

Round trip delay (RTD) time measurement technique is an easy way to obtain the information regarding above issues in WSN. The method of fault detection is based on RTD time measurement of RTPs. RTD times of discrete RTPs are compared with threshold time to determine failed sensor node. Initially this method is tested on 6,30 sensor nodes Round-trip delay (RTD), also called as round-trip time (RTT), is the time required for a signal pulse or packet to travel from a specific source node thru path consisting other nodes and back again. The round trip delay time can range from a few milliseconds (thousandths of a second) under ideal conditions between nearby spaced sensor nodes to several seconds under adverse conditions between sensor nodes separated by a large distance.
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Scalable, low-overhead network delay estimation

Scalable, low-overhead network delay estimation

We consider a fundamental technical problem in networks, namely, how to estimate round trip delay times between receivers in a multicast session in a scalable manner. Our main result is a procedure for solving this problem using fewer messages or bits than previously known methods. We integrate this solution with existing reliable multicast protocols – the combined protocols are substantially more scalable than the originals. Furthermore, we provide experimental evidence that our estimation methods are accurate. In what follows, we motivate and define our problem formally before presenting our results. Round trip delay time is a key parameter in unicast and multicast scenarios. In unicast communication such as in conventional TCP, it is used for timeouts at the source. In multicast communication, the estimated delays between all pairs of nodes are used to suppress feedback and repair packets. In recently proposed congestion control mechanisms [1, 2, 3], delay estimation from the source to each receiver in a multicast session is used to compute the possible transmission rate of the source.
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Faulty node detection in wireless sensor network using round trip delay and path

Faulty node detection in wireless sensor network using round trip delay and path

Round trip delay time of the RTP will change due to faulty sensor node. It will be either infinity or higher than the threshold value. Faulty sensor node is detected by comparing the RTD time of RTPs with threshold value. The threshold value is calculated when the whole network is in proper working, depending upon responces from each node, one fix threshold is selected. The sensor node common to specific RTPs with infinity RTD time is detected as failed. If this time is higher than the threshold value then this senor node is detected as malfunctioning. Detection time of faulty sensor node depends upon the numbers of RTPs and RTD time. Therefore, RTD time measurement and evaluation of RTPs is must to minimize the detection time.
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Implementation of ultrasonic ranging and fire safety for blind person

Implementation of ultrasonic ranging and fire safety for blind person

The device attaches to the golf grip handle of a long cane or onto gloves which is worn by the blind person. A headphone provides audio feedback. The device comes with headphones and an instructional audiotape with sample sounds and a vibrator which vibrates when obstacle is detected. The device also incorporates a fire sensor to alert the blind person if fire is detected. Ultrasonic sensors are based on the output waveform whose pulse width varies with round trip delay time of ultrasonic pulse or distance measured.
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On the Geolocation Bounds for Round-Trip Time-of-Arrival and All Non-Line-of-Sight Channels

On the Geolocation Bounds for Round-Trip Time-of-Arrival and All Non-Line-of-Sight Channels

which brings the advantages of lowered Doppler, reduced delay uncertainty, higher signal strength, and lack of iono- spheric effects. We also assume Rayleigh fading of the sig- nals (implying that the Cramer-Rao bound becomes a ran- dom variable) and different average SNR at each sensor due to pathloss and shadowing. Two other assumptions should be mentioned up front. We will restrict ourselves to the case of flat fading only, as it has been shown [3] that multipath actually improves the CRLB slightly (theoretically, it is not a degradation), while introducing numerical complications. Also, certain advanced location receivers, using integrated carrier phase [11, 12], are able to achieve extraordinary lo- cation accuracy by examining the carrier signal phase prior to mixing to baseband. These systems currently have severe limitations in terms of the time-to-fix, and the allowed initial position uncertainty, so we restrict ourselves to traditional baseband processing.
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Accurate and Integrated Localization System for Indoor Environments Based on IEEE 802 11 Round Trip Time Measurements

Accurate and Integrated Localization System for Indoor Environments Based on IEEE 802 11 Round Trip Time Measurements

way in which the PCB works is as follows: the MU enables the measuring system before sending the RTS frame and disables it after receiving the CTS frame response. Within that time the PCB extracts both transmission pulses and receiver signals from the MU wireless adapter in such a way that the RTS frame departure is used as the trigger to start the count that would be stopped by the corresponding CTS frame arrival. Despite the short lapse of time between the measuring system activation and the RTS departure or between the RTS departure and the CTS arrival, a frame coming from other wireless nodes could interfere activating or deactivating the count, respectively. As this interference could occur, a filter which rejects measurements out of the expected range has been implemented. After the RTS/CTS handshake is completed the MU saves the state of the count. The measuring system proposed has some limitations. Firstly, as the CLK that governs the PCB is 44 MHz frequency, the 16-bit counter implemented on the PCB cannot measure RTTs over 1.489 ms, but this time is enough for wireless networks range. Secondly, as a frame coming from other wireless nodes could activate or deactivate the count within the short lapse of time in which the measuring system is enabled, a filter that rejects these undesirable measurements is implemented. Filter limits have been chosen based on previous trials where there were no other wireless nodes interfering. Finally, according to [12] the elapsed time in the AP, between receiving an RTS frame and sending the corresponding CTS frame, can be assumed to be constant when there are no other processes competing for the AP resources. Obviously, although the RTS frame has the highest priority in [19], it could be concurrent RTS frames coming from other MUs at the same AP increasing the load of the AP. In that case, if there are not enough APs in range to apply the localization algorithm, the wireless localization system delay increases, but the accuracy is not degraded thanks to the previous filter that rejects the RTT measurements that are out of the expected range.
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Improving Efficiency to Transfer Data in Under Water Sensor Networks

Improving Efficiency to Transfer Data in Under Water Sensor Networks

mobility of the sensor nodes .But in case of MU- Sync it considers the node mobility, but it is not energy efficient. Whereas in Mobi-Sync, high energy efficient time synchronization algorithms has been designed for mobile UWSNs [15] but Mobi-Sync is considered only for dense networks. So other methods such as DA-Sync [10] methods have been introduced .The recently introduced technique is the cluster based secure synchronization approach where the nodes have been grouped into clusters and the cluster head manages the time synchronization of these nodes. A Similar process has been done in MU-Sync but it applies half of the round trip time in order to calculate the propagation delay, which can contain many significant errors when sensor nodes move rapidly, whereas in cluster based approach (CLUSS) [5] reduces synchronization errors as well as energy consumption compared to that of other methods In this paper, we discuss a number of techniques along with their benefits and issues in underwater sensor networks. A comparative study of these techniques used in UWSNs has been elaborated. A thorough understanding and differentiation of each of these techniques have been tabulated in Table I and an easy overview is been provided regarding the time synchronization in UWSN.
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PERFORMANCE EVALUATION OF CONGESTION CONTROL PROTOCOLS TCP-RENO, VEGAS, LP, WESTWOOD IN WIRELESS NETWORK

PERFORMANCE EVALUATION OF CONGESTION CONTROL PROTOCOLS TCP-RENO, VEGAS, LP, WESTWOOD IN WIRELESS NETWORK

“Performance evaluation of congestion control protocols (TCP-Reno, Vegas, LP, Westwood) in wireless network” in that the wireless communication Transmission Control Protocol (TCP) plays a vital role in developing communication systems which provides higher and reliable communication capabilities in most styles of networking atmosphere. This paper concentrates on comparative study of the various congestion management protocols supported some performance metrics (Packet Delivery Ratio, Throughput, End2End delay) with some basic scenarios like- RTT(Round Trip Time) and Error Probability. The purpose of this paper is to control congestion and improve performance of congestion control protocols which is implemented in Network Simulator (NS-2). Fairness is a vital and knowledge domain topic used in several fields. This text conjointly discusses fairness index of TCP protocols in wireless networks.
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IMPROVED TCP VEGAS: EFFICIENT CONGESTION CONTROL TECHNIQUE FOR IMPROVING THE PERFORMANCE OF MANET

IMPROVED TCP VEGAS: EFFICIENT CONGESTION CONTROL TECHNIQUE FOR IMPROVING THE PERFORMANCE OF MANET

TCP Vegas is an end to end approach that emphasizes packet delay, rather than packet loss and implemented at sender site. TCP Vegas for Ad hoc network is a congestion avoidance protocol that uses conservative approach to determine and control network state. But this conservation scheme is not good in all conditions and it can unnecessarily reduce the size of congestion window. This paper proposes improved TCP Vegas an improvement over TCP Vegas in Ad hoc network that utilizes round trip time variation of packets at sender side, short term throughput and inter-delay difference at receiver side to measure the network state and then controls congestion window considering the path length and network state. Simulation results show the improvement of 5 to 15 % over Ad hoc TCP Vegas in high mobility and high traffic conditions.
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Design and Performance Analysis of OpenFlow-Enabled Network Topologies Using Mininet

Design and Performance Analysis of OpenFlow-Enabled Network Topologies Using Mininet

Next, comparison of three topologies is done on the basis of delay between nodes in a network. This can be achieved by finding out the round-trip time (rtt) between nodes by executing ‘ping’ connectivity test. A round-trip delay between nodes for different network topologies with variable PTR is tabulated in Table 3 and is shown graphically in Fig. 8 and Fig. 9 for minimum and maximum delay respectively.

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FAULT NODE DETECTION IN WIRELESS SENSOR NETWORK BASED ON ROUND TRIP DELAY

FAULT NODE DETECTION IN WIRELESS SENSOR NETWORK BASED ON ROUND TRIP DELAY

Wireless sensor networks (WSNs) with Portable sensor nodes are a large number of potential applications such as surveillance, security, military operations, and medical, environmental and industrial inspection fields. Due to the rapid enhancement of electronic production technology it is possible to produce the cost of portable sensor node with good accuracy and sensitivity. Therefore, large portable sensor nodes can be used in the area to maximize the quality of such wireless sensor network service. Practice increases such sensor node errors in such WSNs, sensor nodes are used extensively. Such faulty sensor nodes based data analysis is wrong or different from the mean value. This will eventually degrade WSNs service quality. WSNs may be corrupted by sensor nodes such as battery failure, environmental impact, hardware or software errors for various reasons. Such faulty sensor node data rejection in analysis has achieved a good quality service. These WSNs require efficient and accurate detection of faulty sensor nodes. The faulty sensor node is used in different ways to measure Round Trip Delay (RTD) time of discrete round trip paths in the form of comparison with threshold value First, the proposed method of
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A New Scheme for IPv6 BD TTCS Translator: A Section Division Approach

A New Scheme for IPv6 BD TTCS Translator: A Section Division Approach

In this paper we have concluded the various performance issues of D&C based IPv6 ALPM in BD-TTCS Translator with respect to packet loss, round trip time, delay (latency) etc. We performed a simulative evaluation of a performance analysis of D&C based IPv6 ALPM using a novel RST algorithm in ns-2 for a scenario comprising up to 4 levels from level-0 to level-4 and it has 8 slices from slice0 to slice7.We also implemented and simulated a complex data structure concept like D&C based IPv6 ALPM using a novel RST algorithm in BD-TTCS Translator. It is also possible to prove the D&C based IPv6 ALPM using a novel RST is an innovative, challenging and qualitative research problem for future innovative researchers. The future work will focus on IPv4/IPv6 transition algorithm Implementation and Performance issues with singly linked list in NS2 Simulator.
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Indoor Location Based on IEEE 802.11 Round-Trip Time Measurements with Two-Step NLOS Mitigation

Indoor Location Based on IEEE 802.11 Round-Trip Time Measurements with Two-Step NLOS Mitigation

The PNMC method relies on the statistical distribution of NLOS errors and on the major variance that NLOS errors present with respect to LOS. The distribution type of NLOS errors depends on the particular environment. Hence, it can follow different statistical distributions such as Gaussian, Exponential, Gamma, etc. [15]. Regarding the distribution, its parameters can be assumed to be constant in that particular environment. Moreover, those parameters can be obtained before the process of getting distance estimates [27] or directly from the estimated delay spread at that moment [28]. In this paper, those parameters have been obtained beforehand by a campaign of RTT measurements in NLOS.
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Swept-frequency feedback interferometry using terahertz frequency QCLs: a method for imaging and materials analysis

Swept-frequency feedback interferometry using terahertz frequency QCLs: a method for imaging and materials analysis

lish the self-consistency of the scheme, this approach is adopted for each of the three materials in turn. In order to exclude the effects of the boundary between the materials and the alu- minium holder we use measurements from inside the circles superimposed on the photograph in Fig. 3(a) to determine the complex refractive index of each material under test. Referring to Fig. 1(a), the total phase delay in the external cavity can be decomposed into the transmission phase delay arising from the round-trip through the cavity and the phase change on reflection from the target, which is material dependent. The second order effect of the linear current sweep is a linear chirp of the lasing frequency (600 MHz), leading to a linear dependence of trans- mission phase with time. Therefore the external phase delay (interferometric phase) ϕ over one frequency modulation period T as a function of time is of the form
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Optimization of Passive Optical Burst Switching Networks

Optimization of Passive Optical Burst Switching Networks

Patel Bhumika G. [1] mathematically analyzed the Engset Model for the burst blocking probability and burst length for different Round Trip Delay, Average Packet Arrival Time and also analyzed the average Delay for fiber capacity and Burst Size which was made using a delay model and demonstrated that burst length and burst aggregation time should be chosen according to traffic so that blocking probability was reduced and minimum of resources was used in the network.

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Performance Analyses of TCPWestwood

Performance Analyses of TCPWestwood

Network congestion occurs when many hosts try to send data at high rate. And due to queue delay occurs in network and sender retransmit data in order to compenstate lost packet. So, average transmission capacity of routers are reduced. TCP controls its transmission rate by reducing its unacknowledged segments called TCP windows size. TCP congestion control mechanism is based on dynamic window adjustment. In a TCP congestion control mechanism connection is starts with slow start phase and congestion window size is doubled every round trip time until window size reaches slow start threshold. After threshold windo w size is increased by one packet per round trip time. If packet loss occur then threshold size is set to half of current size and window size is set to one segment. congestion avoidance mechanism maintains low delay and high throughput at sender side in network. TCP reno is most adopted TCP schemes and it has good throughput in wired network but performance of reno is worse in wireless network. TCP reno doesn’t distinguish network congestion and wireless loss. Wireless loss is not a network congestion so, TCP does not have to process wireless loss as network congestion. Only TCP mechanism can not distinguish network congestion and wireless loss. So, for this TCP westwood is deployed which controls network congestion and wireless loss effectively. In this paper we see mechanism of TCP Westwood and performance of westwood compared to other congestion control algorithms.
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STUDY AND ANALYSIS OF DIFFERENT TASTES IN TCP TRAFFIC

STUDY AND ANALYSIS OF DIFFERENT TASTES IN TCP TRAFFIC

ii) TCP Vegas :-The major drawback in TCP Reno is that it does not receive fair share of bandwidth. In TCP Reno while a source does not detect any congestion,it continues to increase its window size by one during one round trip time obviously the connections with shorter delays can update the connections with shorter delay can update their window sizes faster than those with longer delays and thus faster than those with longer delays and thus steal higher bandwidth. It is harmful to the other version of TCP Connection with longer delays.
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An IoT Aware MEMS Cardio Care

An IoT Aware MEMS Cardio Care

Fig-5 shows two cases that clearly explain the concept of atherosclerosis and how our system detects plaque detection. For our system, we have considered time T, which is the Round Trip Time required by the ultrasound waves to get back to the MEMS device. If no delay is observed, (i.e.) when all the waves, that are sent, are received back at the same prefixed Round Trip Time of Micro-SONAR, we can conclude that no plaque has formed. In the second case, as the picture shows, plaque formation has taken place. Here we split T in two part as T1 and T2. T1 is the Round Trip Time required to receive the waves, which reflected without reaching the arterial wall. T2 is the Round Trip Time required to receive the waves, which penetrated the plaque, reached the arterial wall and came back to the MEMS device.
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A study of polymerase chain reaction device control via cloud using Firebase Cloud Messaging protocol

A study of polymerase chain reaction device control via cloud using Firebase Cloud Messaging protocol

Previous studies have shown that PCR devices can be controlled via the cloud [11]. However, when various data are exchanged, the round-trip time increases as the size of data increases. As a result of the experiment, no problem occurred in the PCR which transmits the protocol at a time. But it was judged that it can cause problems in real-time PCR. Real-time PCR can monitor the amplification process in real time and quantify the amount of amplification [12]. Since Representational State Transfer (REST) Protocol used in previous research is operated on HTTP basis, it is heavy and slow to collect con- trol information and sensor information of small devices. This study uses the messaging technology supported by Firebase to exchange commands and data from PCR devices. Firebase Cloud Messaging (FCM) can transfer up to 4  kB of payload to client apps. Therefore, in this study, the round-trip experiment to measure the time to exchange data with the real-time database using FCM was repeatedly performed. Through this experi- ment, we confirmed the communication speed and determined the delay time value which can cause the operation of the PCR device.
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