Multi Path Research Articles

Hybrid RSAECC Based Secure Communication in Mobile Cloud Environment

Mobile computing gained much attention in current research arena due to the enhancement of services such as mobile learning, health care monitoring and e commerce. The experience and satisfaction which increases the user count in millions on every day. Advantage of using cloud computing for essential multipath communication creates path for multi homing architecture and multi path data transmission. While the technology develops the security breaches are also increases due to the increased number of users and loads. System has to be considered as stable and safe only if breaches are reduced. Based on the applications services has to be enhanced with reliability, less faults, and robustness makes end to end communication much better for the future. The proposed research work describes a secure cloud computing mobile environment which provides meritorious service to the users. Experimental results highlights the proposed model has 98.5% of success ratio on providing secure communication services to the users via cloud computing applications.

Non Linear Differential Optimization for Quality Aware Resource Efficient Routing in Mobile Ad Hoc Networks

MANETs is the basic structure less network in which mobile nodes connecting point at which several line comes together to form a network structure. Network resources in MANETs are limited due to their forcefulness study of a given place. A mobile node in MANETs utilizes an interconnected system of things such as data transmission rate and battery power during data packet transmission. Thus the conserving network resource is important to maintain the quality of network services without delay. Therefore, Non-linear Differential Resource Optimization based Quality Aware Routing (NLDRO-QAR) Technique is proposed. The NLDRO-QAR Technique selects the resource optimized route path among multi paths for efficient data packet transmission in MANETs. The resource optimized route path is determined in proposed NLDRO-QAR Technique by choosing mobile node with higher resource availability as optimal nodes. The NLDRO-QAR Technique considers residual energy, residual bandwidth, and delay time as significant factor for computing resource availability of mobile nodes in MANETs. In order to effectively find out the optimal nodes (i.e. mobile node with higher resource availability) in dynamic environment. The NLDRO-QAR Technique chooses the resource optimized nodes in MANETs in order to transmit the packets between source and destination. As a result, NLDRO-QAR Technique efficiently reduces the energy and bandwidth utilization of data delivery in MANETs. The NLDRO-QAR method manage the simulation works on metrics such as energy utilization, average end to end delay, data loss rate and bandwidth utilization rate. The simulations results show that the NLDRO-QAR Technique is able to reduce the energy and bandwidth utilization for routing the data packet in MANETs as compared to state-of-the-art-works.

A Novel Opinion Computational model of multi path POR Routing Protocol based on subjective logic in Mobile Ad hoc Networks

A Novel Opinion Computational model of multi path POR Routing Protocol based on subjective logic in Mobile Ad hoc Networks

MP mitigation in GNSS positioning by GRU NNs and adaptive wavelet filtering

In urban canyons, multipath (MP) signals have some problems such as short time delay, high dynamic, and uncontrollable. To solve this problem and mitigate the interference of MP effect on positioning, the authors proposed a new method which uses gated recurrent unit (GRU) neural networks (NNs) aided by compressed sensing algorithm to estimate parameters of MP signal accurately. They showed how to build the GRU - deformation of recurrent NNs (RNNs) - in a dynamic environment, and estimated the MP signals parameters accurately. Also, considering the special cases in a dynamic environment, they used the adaptive wavelet filter to optimise the NNs, compensated pseudo-distance, and improved the accuracy of positioning. Like other NNs, the learning process of this machine learning method in the dynamic environment can be summarised as obtaining data from different environmental conditions. For this, they collected signal data from different speeds to train GRU-RNN model, which correctly estimated the MP signal's parameter value in a different environment and different speeds. By experimental verification, when the speed is slower than 20 km/h, GRU-RNN can reduce code tracking error to 0.08 chips, and increased the positioning accuracy by about 13%.

Performance Analysis of MIMO-OFDM System Based on SVD scheme under multi path selective fading channel

We consider in this paper a MIMO-OFDM wireless communication system based on pre-coding and SVD techniques, which the system has the feedback of CSI to the transmitted side. The multi path channel, delay spread, Rayleigh fading and channel noise are assumed in the simulation of the proposed system. The zero forcing method is applied for detection the data received. The goal of our study is to evaluate the BER performance and see it with different case. The BER resulted shows the improvement by using the SVD decomposition for the associated system of MIMO-OFDM. Particularly in the complex conditions of wireless channel where we considered ten paths for propagation the signals between transmitter and receiver sides. And also the contribution is appeared when the system studied keeps a good BER performance when the data rate is increased by using more transmit antenna. As we evaluated the BER of MIMO-OFDM system done for various sub-carriers and in two guard interval lengths for the OFDM system

Video Transmission In Wireless Multihop Networks

Multi hop wireless networks are being deployed in many video streaming applications because they have several potential features for next generation wireless communications. Though optimal encoding techniques offers significant quality retention in video transmission still it is insufficient to overcome the challenges ahead over wireless network transmission. In order to support wide range video communications in an efficient way certain Quality of service has to be retained in multi hop wireless network. To address this issue, this paper investigates several encoding and routing protocols video delivery over multi hop wireless networks. Specifically, we first investigate several encoding framework for videos and wireless data transmission over WMNs through individual paths; we then investigate the challenges ahead to formulate resistant routing model for least possible video quality dictions which incorporate channel status as well as the encoder properties over video characteristics. In this framework, routing techniques which can maximally used to achieve good video traffic with improved system performance. However, video streaming also have very stringent delay requirements, which makes it difficult to find optimal routes with the least possible distortions. To address this problem, we investigate several enhanced version of packet scheduling techniques for video communications over multi path multi hob multi user wireless network environment.

Analysis of the Multipath Scattering Effects in High-Resolution SAR Images

Due to multipath (MP) scattering, many special phenomena and details about the targets in high-resolution synthetic aperture radar (SAR) images are hard to understand. In this letter, a more elaborate improved model combined with the synthetic aperture progress is presented, to analyze the MP scattering. We explore the defocusing and displacement phenomena of MP scattering through signal modeling and time–frequency relationship analysis. The theoretical equations for the displacement of double scattering are derived, and the equation of phase error which causes the defocusing is also given. The SAR raw data simulation of MP scattering and range-Doppler (RD) imaging results validates the correctness of the analysis. From the equations, the effects of MP scattering of different height and different orientation angle in high-resolution SAR images are given. Finally, based on the simulation results, the new interpretation about the relationship between the moustache effect in high-resolution TerraSAR-X SAR images and the height of the structure is obtained.

On the soft multi fundamental group

The theory of soft set is one of the most important method in solving uncertainties in various real-life problems. The main aim of this paper is to define soft multi fundamental group. The notion of soft multi group, soft multi path, soft multi loop, and soft multi homotopy are to be introduced and their basic properties are also to be investigated. Further, the concept of soft multi homeomorphism is introduced. Added to, we established certain properties and operations on soft multi fundamental group.

Simulation Based Performance Evaluation of AOMDV Routing Protocol in Mobile Ad Hoc Networks Using NS2

Due to the increased use of mobile devices with the high demand for applications such as CBR: Constant bit rate، most companies have tended to pay attention to Mobile Ad hoc Networks and search for solutions to the problems and obstacles encountered. The routing process of this type of networks was one of the solutions addressed: multi-path routing، which is used with on-demand protocols and the aim of this is to obtain efficient and fast retrieval of routes that failed in dynamic mobile networks because mobile nodes can randomly join or leave to/from the topology that may increase/decrease the node density and frequent link failures in the topology. As a result node density، traffic and transmission range effects the performance of the network. In this paper، a proposed multi-path routing protocol is AOMDV ad hoc on demand multi path distance vector routing protocol، which is the expansion of the AODV single path ad hoc on demand distance vector routing protocol.Therefore، In this paper، we has been studied AOMDV routing protocol which is a multipath routing protocol on the basis of Throughput، Delay، Packet-Loss and Jitter and evaluated the performance by varying pause time and varying maximum speed of the moving nodes and for 5،10،50 nodes.

An Improved Delay Resistant Adaptive Multicasting Strategy for High Definition Video Delivery in Wireless Overlay Network

The Multimedia based application services have been getting attention in recent years in various fields. These services require a stringent delay resistant protocol in order to provide the best Quality of Service to end users. Existing protocols are predominantly designed using load balancing, tree, multi-tree and mesh based mechanisms. These mechanisms suffer in the presence of channel noise and incur more delay due to improper multicasting techniques adopted. Overlay network using hybrid (tree over mesh) structure along with multicasting strategies are used to address this issue. In this paper, an Improved Delay Resistant Adaptive Multicasting (IDRAM) model which adopts hybrid overlay creation, sub-packet based multi path transmission technique and error correction based on Forward Error Correction along with arbitrary IDRAM-A and selective IDRAM-S multicasting techniques are proposed and evaluated. Simulation is conducted to calculate frame success ratio, throughput, number of packet retransmission and transmission delay. The results obtained prove that IDRAM-S outperforms better than IDRAM-A and existing sub packet based multi path techniques. The number of retransmission requests made by IDRAM-S is reduced compared to the existing model. This reduction in the number of retransmission enables in minimizing end to end delay and thereby achieve stringent delay constraints associated with multimedia data delivery.

Control and Decision Making for Ocean Feature Tracking with Multiple Underwater Vehicles

ABSTRACT Zhang, S. and Li, C., 2018. Control and decision making for ocean feature tracking with multiple underwater vehicles. In: Liu, Z.L. and Mi, C. (eds.), Advances in Sustainable Port and Ocean Engineering. Journal of Coastal Research, Special Issue No. 83, pp. 552–564. Coconut Creek (Florida), ISSN 0749-0208. Autonomous Underwater Vehicles (AUVs) are mobile platforms with excellent maneuverability, which are preferred for microscale and mesoscale ocean feature tracking in near real time mode. With their good maneuverability and low cost, AUVs make autonomy mobile observation of ocean dynamic process feasible and convenient. Aiming for the observation of the typical microscale and mesoscale oceanographic features near South China Seas, we give thorough discussion of control and tracking strategy with AUVs. Firstly, we give the composition of autonomy observation system, mainly including vehicle dynamic control, multi underwater vehicles path plan and data process. Secondly, considering the driving fa...

English

English

An EM-based multipath interference mitigation in GNSS receivers

In multipath (MP) environments, the received signals depend on several factors related to the global navigation satellite systems (GNSS) receiver environment and motion. Thus it is difficult to use a specific propagation model to accurately capture the dynamics of the MP signal when the GNSS receiver is moving in urban canyons. This paper formulates the problem of MP interference mitigation in the GNSS receiver as a joint state (containing the direct signal parameters) and time-varying model parameter (containing the MP signal parameters) estimation. Accordingly, we propose to exploit the EM algorithm for achieving the joint state and time-varying parameter estimation in the context of MP interference mitigation in GNSS receivers. More precisely, the proposed EM-based MP mitigation approach is decomposed into two iterative steps: (a) the posterior pdf of the direct signal parameters and the expected log-likelihood function necessary in the expectation step of the EM algorithm are approximated by using an appropriate particle filter; (b) the maximum likelihood solution for MP signal parameters is then obtained using Newton’s method in the maximization step. The convergence of the proposed approach is analyzed based on the existing convergence theorem associated with the EM algorithm. Finally, a comprehensive simulation study is conducted to compare the performance of the proposed EM-based MP mitigation approach with other state-of-the-art MP mitigation approaches in static and realistic scenarios.

SDN based Multi Path Routing for Efficient Cost Minimization - Advanced Networking Algorithm

SDN based Multi Path Routing for Efficient Cost Minimization - Advanced Networking Algorithm

Multipath Mitigation for GNSS Positioning in an Urban Environment Using Sparse Estimation

Multipath (MP) remains the main source of error when using global navigation satellite systems (GNSS) in a constrained environment, leading to biased measurements and thus to inaccurate estimated positions. This paper formulates the GNSS navigation problem as the resolution of an overdetermined system whose unknowns are the receiver position and speed, clock bias and clock drift, and the potential biases affecting GNSS measurements. We assume that only a part of the satellites are affected by MP, i.e., that the unknown bias vector has several zero components, which allows sparse estimation theory to be exploited. The natural way of enforcing this sparsity is to introduce an $\ell _{1}$ regularization associated with the bias vector. This leads to a least absolute shrinkage and selection operator problem that is solved using a reweighted- $\ell _{1}$ algorithm. The weighting matrix of this algorithm is designed carefully as functions of the satellite carrier-to-noise density ratio ( $C/N_{0}$ ) and the satellite elevations. Experimental validation conducted with real GPS data show the effectiveness of the proposed method as long as the sparsity assumption is respected.

Analysis of Galileo/BDS/GPS signals and RTK performance

New satellites and signals become available with the modernization of GNSS, especially for Galileo and BDS. The current Galileo constellation comprises 4 IOV (in-orbit validation) and 14 FOC (full operational capability) satellites which transmit signals on five frequencies. In addition to BDS-II regional navigation system, five BDS-III experimental (BDS-IIIs) and eight BDS-III satellites have been launched. It is worthwhile to evaluate the performance of these new satellites and signals. First, these signals are assessed in regard to carrier-to-noise density ratio (C/N0), code multipath (MP) combination, and triple-frequency carrier phase ionospheric-free and geometry-free (DIF) combination. The C/N0 of Galileo IOV satellites is several dB-HZ lower than that of the FOC satellites, while that of the IOV satellite E19 is always the lowest, regardless of receiver type. As for BDS, the C/N0 of the BDS-IIIs are higher than that of BDS-II but lower than that of BDS-III. The difference of C/N0 among GPS satellites is not obvious. Among all the signals, the performance of E5 is the best which may be related to its advanced modulation scheme, while the L2 is the worst. The code multipath on E5 is independent of the satellite elevation due to its good MP suppression performance, which may be related to its wide signal bandwidth. The RMSs of MP for Galileo signals are even smaller than that of GPS. Being free of the systematic code errors of BDS-II, the RMS of BDS-IIIs MP errors is comparable with that of GPS and Galileo. In addition, the multipath errors show an obvious periodic behavior, which differs with the types of satellites. Similarly, the DIF combinations also possess elevation-dependent and periodic characteristics. Note that the inter-frequency bias variations present in BDS-II and GPS IIF satellites are absent for Galileo satellites. The accuracy of Galileo SPP is comparable to that of GPS, but better than that of BDS. Although there are no significant differences for the RTK results of the three systems, the double-differenced carrier phase and code residuals of E5 is the smallest among all the signals.

Multipath Scattering of Typical Structures in Urban Areas

Recent advances in very high-resolution tomographic synthetic aperture radar (SAR) inversion using multiple data stacks from different viewing angles enable us to reconstruct the reflectivity function along the elevation direction by means of spectral analysis for every azimuth-range pixel. They can be potentially used for facade reconstruction and deformation monitoring in an urban area. When SAR tomographic processing is used to form 3-D point clouds, some points that we simply omitted in the traditional 3-D reconstruction are difficult to understand. It comes to our attention that this special detail which seems violated to a common practice is due to the mechanism of multipath (MP) scattering. Dominated by SAR tomography process, MP scattering reveals many interesting phenomena in 3-D point clouds. In this paper, a theoretical model of the MP scattering of the structure of dihedral corner which often appears in the urban area is given. There are two groups of points distributed symmetrically and compactly around the base angle of the building. The positions of these two groups of the points can be predicted by our model. Corresponding experiments are carried out to show the validity. The position is relative to the height of the building which indicates a direct utilization of our model to estimate the height of the building directly without 3-D reconstruction.

Secure Multipath Mutation SMPM in Moving Target Defense Based on SDN

Software-defined networking (SDN) refers to a network architecture where the transfer state in the data plane is managed by a remote control plane in a centralized manner. SDN offer many advantage in terms of flexibility and automation to administrator but it suffer from many security issues. In other hand, Random Route Mutation (RRM) and path diversity represent one of the important research focuses about moving target defense (MTD). The main idea of using this technic, is to change periodically (or basing on events) used routes between sender and receiver in order to enhance mutation efficiency and decrease attackers capabilities to launch effective eavesdropping, denial of service or man in the middle attack. Using RRM and multi path technics can be very interesting in order to secure SDN and to detect and prevent intrusions. In this paper it is propose a new framework called SMPM which aims to secure and prevent intrusion by modeling SDN architectures and using a pathfinder algorithm called RRM-Pathfinder. The proposed framework calculates all possible paths from given source to destination and then, based on some criteria such as capacity, Overlap, Security and QoS, it selects and identifies the most cost-effective routes. The use of SMPM allow also to dynamically route packets using all pre-calculated paths which will permit to avoid sniffing and poisoning attacks such as Arp spoof and the man in the middle attacks and to ensure more confidentiality, integrity and privacy.

ANALYSES OF DIFFERENT PROTOCOLS FOR MULTIPATH ROUTING IN WSN

Modern progress in Wireless Sensor Networks (WSNs) for instance observation, traffic observation as well as storeroom of probable applicable are planned to cherish the authentic planet. For these network severe necessities of quick, dependable protocol to convene the restraint that is latency, highest packet received ratio, good put as well as energy efficiency. In this article we have reviewed the several multi path routing protocols such as Energy Efficient Multi Path (EEMP) routing protocol, Secure and Energy efficient Multi Path (SEMP) routing protocol, Bandwidth Aware Multi Path (BAMP) routing protocol, Cooperative Multi Path (CMP) routing protocol as well as QoS Multi Path (QoSMP) routing protocol. The simulation of multi path routing is offered depend on packet received ratio, average delay as well as energy efficiency in WSN.

Early analysis of precise orbit and clock offset determination for the satellites of the global BeiDou-3 system

Eight new-generation BeiDou satellites (BeiDou-3) have been launched into Medium Earth Orbit (MEO), allowing for global coverage since March 2018, and they are equipped with new hydrogen atomic clocks and updated rubidium clocks. Firstly, we analyzed the signals for the carrier-to-noise-density ratio (C/N0) and pseudorange multipath (MP) by using international GNSS (Global Navigation Satellite System) Monitoring and Assessment System (iGMAS) station data, and found that B1C has a lower C/N0, and B2a has the same level of C/N0 as the B1I and B3I signals. For pseudorange multipath, compared with the BeiDou-2 satellites, the obvious systematic variation of MP scatters related to the elevation angle is greatly improved for the BeiDou-3 and BeiDou-3e satellites signals. For the signals of the BeiDou-3 satellites, the order of the Root Mean Square (RMS) values of multipath and noise is B3I < B1I < B2a < B1C. Then, the comparison of the precise orbit determination and clock offset determination for the BeiDou-2, BeiDou-3, and BeiDou-3 experimental (BeiDou-3e) satellites was done by using 10 stations from iGMAS. The 3D precision of the 24 h orbit overlap is 24.55, 25.61, and 23.35 cm for the BeiDou-3, BeiDou-3e, and BeiDou-2 satellites, respectively. BeiDou-3 satellite has a comparable precision to that of the BeiDou-2 satellite. For the precision of clock offset estimation, the Standard Deviation (STD) of the BeiDou-3 MEO satellite is 0.350 ns, which is an improvement of 0.042 ns over that of the BeiDou-2 MEO satellite. The stabilities of the BeiDou-3 and BeiDou-3e onboard clocks are better than those of BeiDou-2 by factors of 2.84 and 1.61 at an averaging time of 1000 and 10,000 s, respectively.