Linear analysis of a terahertz staggered double-grating arrays waveguide Cerenkov traveling wave amplifier

Based on a sheet electron beam propagating through the tunnel of a staggered double-grating arrays waveguide (SDGAW) slow-wave structure (SWS), a three dimensional linear theory for describing beam-wave interaction is presented, in which the higher order terms inside the groove were retained.

With the optimized parameters, a 1THz SDGAW Cerenkov traveling wave amplifier (CTWA) may obtain a moderate net gain larger than 10dB/cm in 0.92THz to 1.145THz considering the serious Ohmic losses in THz frequency range.

Analysis of effect of mobility and transmission power on AODV and DSR in mobile Adhoc network

Now a days there is a remarkable growth in telecommunication technology which makes users of mobile electronic devices accessible to a communication network. These electronic devices are nothing but the nodes of the Mobile Ad hoc Network (MANET). Each node can move from one place to other during communication and this mobility is having its effect on performance of the network. Mobility changes when speed of the node and pause time with which it moves changes. Change in mobility causes break of link with neighboring nodes as a result of which the performance of a network may be reduced.

A number of packets are dropped at different layers of the network. This paper describes the analysis of change in performance due to change in mobility and transmission power. The parameters describing the reason of variation in performance are (1) number of link breaks and (2) number of packet delivered. (3)End to end delay. The simulator we have used in our work for the calculation of performance matrices is GLOMOSIM. The performance comparison has also made between two types of on demand routing protocols AODV and DSR.

Can you trust your fridge?

The Internet of Things has been touted as many things. But what you haven’t heard is that it could be your worst enemy. Yet all of these incidents have actually occurred, according to news reports. And it’s likely that even more disturbing transgressions have been taking place unbeknownst to homeowners. For example, researchers have discovered that in some cases, they can hack the Internet of Things to intercept each document you print and divert it to a remote site, use your smart TV to bug your house, and even control the tramc light on the corner outside your home.

The vulnerabilities lie all around you. An HP Research study reported that the average Internet of Things gadget has an astounding 25 security flaws, and 70 percent have at least one such vulnerability. Many of these problems may yield to solutions like those adopted by the personal computer industry decades ago. There are also some that require new approaches that take into account the vast scale and narrow profit margin of the emerging world of Internet augmented products.

C22. Avionics Full-duplex switched Ethernet (AFDX): Modeling and simulation

This paper develops a comprehensive simulation model for Avionics Full-duplex switched Ethernet (AFDX) network based on OPNET platform. Accordingly, the performance of AFDX networks is analyzed. The effect of frame size, switching delay and changing frames transmission order on the AFDX network performance are investigated.

It is found that using faster switches and small frame size reduces the fixed part of the end to end delay. Also, it affects the variable part of end to end delay due to changing of delay in switches’ buffers and frames transmission order.

A Social-Network-Aided Efficient Peer-to-Peer Live Streaming System

In current peer-to-peer (P2P) live streaming systems, nodes in a channel form a P2P overlay for video sharing. To watch a new channel, a node depends on the centralized server to join in the overlay of the channel. In today’s live streaming applications, the increase in the number of channels triggers users’ desire of watching multiple channels successively or simultaneously. However, the support of such watching modes in current applications is no better than joining in different channel overlays successively or simultaneously through the centralized server, which if widely used, poses a heavy burden on the server. In order to achieve higher efficiency and scalability, we propose a Social-network-Aided efficient liVe strEaming system (SAVE). SAVE regards users’ channel switching or multichannel watching as interactions between channels.

By collecting the information of channel interactions, nodes’ interests, and watching times, SAVE forms nodes in multiple channels with frequent interactions into an overlay, constructs bridges between overlays of channels with less frequent interactions, and enables nodes to identify friends sharing similar interests and watching times. Thus, a node can connect to a new channel while staying in its current overlay, using bridges or relying on its friends, reducing the need to contact the centralized server. We further propose the channel-closeness-based chunk-pushing strategy and capacity-based chunk provider selection strategy to enhance the system performance. Extensive experimental results from the PeerSim simulator and PlanetLab verify that SAVE outperforms other systems in system efficiency and server load reduction, as well as the effectiveness of the two proposed strategies.

Modeling distributed denial of service attack in advanced metering infrastructure

Imminent attacks on critical infrastructure can disrupt operations. It also interrupts information availability. One way through cyberspace is to harness the distributed computing power and flood on targeted systems with massive information as a consequence of denial in service. This paper discusses the distributed denial of service (DDoS) attack, a potential cyberthreat in AMI communication network.

A typical DDoS includes two stages: (1) agents recruitment stage and (2) actual attack stage. In this paper, various models of malware installation and flooding attack on AMI devices are introduced and potential impacts are studied. Some particular attack scenario is simulated using NS3. We also discussed the potential defense technologies.

SDStorage: A Software Defined Storage Experimental Framework

With the rapid growth of data centers and the unprecedented increase in storage demands, the traditional storage control techniques are considered unsuitable to deal with this large volume of data in an efficient manner. The Software Defined Storage (SDStore) comes as a solution for this issue by abstracting the storage control operations from the storage devices and set it inside a centralized controller in the software layer. Building a real SDStore system without any simulation and emulation is considered an expensive solution and may have a lot of risks.

Thus, there is a need to simulate such systems before the real-life implementation and deployment. In this paper we present SDStorage, an experimental framework to provide a novel virtualized test bed environment for SDStore systems. The main idea of SDStorage is based on the Mininet Software Defined Network (SDN) Open Flow simulator and is built over of it. The main components of Mininet, which are the host, the switch and the controller, are customized to serve the needs of SDStore simulation environments.

Power and Rate Optimization for Visible Light Communication System With Lighting Constraints

Visible-light communication (VLC) will be deployed in various indoor environments, including those requiring different lighting colors, which imposes the needs for transmission optimization under certain lighting constraints. This work establishes a framework for the transmission power and rate optimization, for light emitting diode (LED)-based VLC systems under lighting constraints. We describe the system model of LED-based color-division VLC system, which incorporates the transmission power spectral density, the receiving optical filters, the human eye perception, and the lighting constraints. Then, we formulate the corresponding power and rate optimization problems, for both point-to-pointcommunication system and broadcast communication system.

More specifically, for a point-to-pointcommunication system, it maximizes the transmission rate subject to the transmission power constraint and the lighting constraint; and for a broadcast system, it minimizes the total transmission power subject to some quality of service (QoS) constraint across all receivers. Various convex optimization problems have been formulated and solved analytically or using standard convex optimization solutions. It is obsesrved that the optimal symbol modulation power allocation scheme significantly outperforms the equal power allocation scheme.

Optical Wireless Communication System Using LED and Image Sensor

Light-emitting diodes (LEDs), used in optical wireless communication generally called visible lightcommunication. This paper highlights the implementation of the optical wireless communication system using LED and CMOS image sensor. In this paper, we are going to implement an optical wirelesscommunication system equipped with an optical communication image sensor (OCI), which is newly developed using CMOS technology.

Here we are considering the image pixel (IPx) and communicationpixel (CPx) for quick LED detection and for higher transmission data rates. Also we are going to introduce a new technique called 1-bit flag image technique for quick LED detection.

Communication coverage awareness for self-aligning wireless communication in disaster operations

Broad band communication in international disaster response actions is becoming more and more important. The information exchange between field commanders and tactical commanders lead to a better situational awareness on all layers of disaster management. After large scale disasters thecommunication infrastructure is often destroyed. Setting up a communication infrastructure is essential in todays disaster response actions. As organizations in disaster response actions are not consisting of IT experts, the setup and installation has to be easy. For example [1] presents such a system.

Furthermore the knowledge where to deploy wireless communication gateways and wireless relay nodes is essential. Consequently the positions of field commanders can not only be based on tactical needs but also on communication needs. In this paper we present a simulation based visualization tool which helps to evaluate deployment locations for communication equipment to achieve adequatecommunication coverage with respect to specific disaster related information. This allows an optimal positioning of relay nodes and field commanders in the field to ensure broad band communication in disaster response actions and thus faster help for the people.