Improving Throughput of Transmission Control Protocol Using Cross Layer Approach

Most of the internet users connect through wireless networks. Major part of internet traffic is carried by Transmission Control Protocol (TCP). It has some design constraints while operated across wireless networks. TCP is the traditional predominant protocol designed for wired networks. To control congestion in the network, TCP used acknowledgment to delivery of packets by the end host. In wired network, packet loss signals congestion in the network. But rather in wireless networks, loss is mainly because of the wireless characteristics such as fading, signal strength etc. When a packet travels across wired and wireless networks, TCP congestion control theory faces problem during handshake between them. This paper focuses on finding this misinterpretation of the losses using cross layer approach. This paper focuses on increasing bandwidth usage by improving TCP throughput in wireless environments using cross layer approach and hence named the proposed system as CRLTCP. TCP misinterprets wireless loss as congestion loss and unnecessarily reduces congestion window size. Using the signal strength and frame error rate, the type of loss is identified and accordingly the response of TCP is modified. The results show that there is a significant improvement in the throughput of proposed TCP upon which bandwidth usage is increased.     

Bi2MoO6 hierarchical microflowers for electrochemical oxygen evolution reaction

Solvothermal Bi₂MoO₆ hierarchical microflowers synthesis has been successfully attempted. Methanol, ethanol and isopropanol have been mediated to synthesize three kinds of Bi₂MoO₆ hierarchical microflowers. Highly oriented (311) plane growth of orthorhombic Bi₂MoO₆ hierarchical microflowers have been confirmed. Interstitial vacancies and its role on electrochemical activity have been extensively discussed. Electrode fabrication was constructively done by using Ni foam substrate. Half cell arrangement of each electrode in alkaline medium has been designed to measure the electrochemical activity towards water oxidation. High current density of 356 mA/cm² was afforded by Bi₂MoO₆ hierarchical microflowers mediated by ethanol solvent during synthesis. Low Tafel slope value of 43 mV/dec has been reported to obtain 10 mA/cm² current density. Higher conductivity long with very good electron transportation has been achieved and is also adapted for 12 h long time stability test and achieved 86% of retention in its performance. Hence, optimally prepared Bi₂MoO₆ hierarchical microflowers could be an efficient electrode for clean energy fabrication.     

Multi-Authority-Based File Hierarchy Hidden CP-ABE Scheme for Cloud Security

Cloud technology is emerging as a widely accepted technology in the recent years due to its robust nature. Cloud computation is basically developed on the fact that the resources can be shared between numerous devices to achieve efficient network operation among devices with minimized computation expenses. However, the sharing nature poses a security risk for the devices whose resources are being shared. Almost in all the existing works on cloud security, a single trusted third party (TTP) is used for key issue and authorization. However, using a single TTP may results in single-point failure and security risks. Most of the previous works on cloud security focus on storage security rather than considering the computation security. In order to solve these issues, in this paper, multi-authority-based file hierarchy hidden CP-ABE scheme for cloud security is proposed. In this scheme, the files are arranged in hierarchical order based on their attribute weights. Then when a cloud user needs certain resources, it requests the cloud service provider (CSP). The CSP links with the cloud owner to provide the requested file after encrypting it. The cloud server encrypts and places the encrypted file in CSP, which is later retrieved by cloud user. In this way, all the files that are being used are encrypted along with strict authentication to ensure cloud security.     

Salient object based visual sentiment analysis by combining deep features and handcrafted features

Multimedia Tools and Applications - With the rapid growth of social networks, the visual sentiment analysis has quickly emerged for opinion mining. Recent study reveals that the sentiments conveyed...     

Improvement of Transmission Control Protocol for High Bandwidth Applications

Transmission control protocol (TCP) is the widely and dominantly used protocol in today’s internet. A very recent implementation of congestion control algorithm is BBR by Google. Bottleneck bandwidth and round-trip time (BBR) is a congestion control algorithm which is created with the aim of increasing throughput and reducing delay. The congestion control protocols mentioned previously try to determine congestion limits by filling router queues. BBR drains the router queues at the bottleneck by sending exactly at the bottleneck link rate. This is done by the BBR through pacing rate which infers the delivery rate of the receiver and uses this as the estimated bottleneck bandwidth. But when the data rate is high, in the startup phase itself pipe becomes full and leads to some degradation in the Access Point of wireless environments by inducing losses specific to this environment. So the current pacing rate is not suitable for producing higher throughputs. Therefore, in the proposed system named R-BBR, this startup gain should be lower than the current startup gain which eventually would reduce pacing rate to reduce queue pressure in the sink node during the startup phase. The startup phase of BBR is modified to solve the problem of pipe full under high data rate. R-BBR has been evaluated over a wide range of wired as well as wireless networks by varying different factors like startup gain, congestion window, and pacing rate. It is inferred that R-BBR performs better than BBR with significant performance improvement.

     

Detection of fall for the elderly in an indoor environment using a tri-axial accelerometer and Kinect depth data

Multidimensional Systems and Signal Processing - Monitoring elderly people who are living alone is a crucial task as they are at great risk of fall occurrence. In this paper, we present a robust...     

Hierarchical threshold secret sharing scheme for color images

Multimedia Tools and Applications - The applications that use pattern recognition via secret sharing are seldom linear, straightforward and uncomplicated. The layers of complexity grows as the...     

Copper molybdate nanoparticles for electrochemical water splitting application

Two different phases of copper molybdate nanoparticles such as Cu₃Mo₂O₉ and Cu₆Mo₅O₁₈ were synthesized through schematic hydrothermal treatment. The obtained product morphology was explored by using surfactants like sodium lauryl sulfate (SDS) and polyvinylpyrrolidone (PVP). The structural, optical, vibrational and morphological properties were confirmed employing standard characterization techniques. Rectangular nanoflakes of the obtained product were confirmed by employing Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) studies. Selected area electron diffraction (SAED) pattern confirms obtained product crystalline nature. The better morphology controlled sample gives higher 227 mA/g current density at 10 mV/s and small 184 V overpotential. Long duration stability over 16 h was exhibited by Cu₆Mo₅O₁₈ electrode. Hence, Cu₆Mo₅O₁₈ electrode shows better electrochemical activity with stunning low overpotential. It would be suggested that PVP surfactant is quite optimum to produce efficient Cu₆Mo₅O₁₈ catalysts for electrochemical water splitting applications.     

A novel chaotic map based compressive classification scheme for human activity recognition using a tri-axial accelerometer

Multimedia Tools and Applications - Human activity recognition using wearable body sensors plays a vital role in the field of pervasive computing. In this paper, we present human activity...     

Gradient Based Aura Feature Extraction for Coral Reef Classification

Wireless Personal Communications - Millimeter wave (mmWave) has been regarded as a candidate cellular band for future 5G networks. It exhibits an extension for current cellular bands, where its...