Ns3 Projects for B.E/B.Tech M.E/M.Tech PhD Scholars.  Phone-Number:9790238391   E-mail: ns3simulation@gmail.com

An ME-PC Enhanced HDMR Method for Efficient Statistical Analysis of Multiconductor Transmission Line Networks

An efficient method for statistically characterizing multiconductor transmission line (MTL) networkssubject to a large number of manufacturing uncertainties is presented. The proposed method achieves its efficiency by leveraging a high-dimensional model representation (HDMR) technique that approximates observables (quantities of interest in MTL networks, such as voltages/currents on mission-critical circuits) in terms of iteratively constructed component functions of only the most significant random variables (parameters that characterize the uncertainties in MTL networks, such as conductor locations and widths, and lumped element values). The efficiency of the proposed scheme is further increased using a multielement probabilistic collocation (ME-PC) method to compute the component functions of the HDMR.

The ME-PC method makes use of generalized polynomial chaos (gPC) expansions to approximate the component functions, where the expansion coefficients are expressed in terms of integrals of the observable over the random domain. These integrals are numerically evaluated and the observable values at the quadrature/collocation points are computed using a fast deterministic simulator. The proposed method is capable of producing accurate statistical information pertinent to an observable that is rapidly varying across a high-dimensional random domain at a computational cost that is significantly lower than that of gPC or Monte Carlo methods. The applicability, efficiency, and accuracy of the method are demonstrated via statistical characterization of frequency-domain voltages in parallel wire, interconnect, and antenna corporate feed networks.

SCUMG: Secure Code Update for Multicast Group in Wireless Sensor Networks

Securing code update is essential for military and health care applications. The functionalists of the sensor nodes in military and health monitoring region depend on their environmental conditions. The sensor nodes will be divided into different multi cast groups based on their location. For each multi cast group a different code update will be sent. We have developed a scheme for secure code update for multi-cast groups.

In order to securely communicate the code update for each multi cast group, a key agreement protocol is developed. This protocol provides confidentiality and immediate authentication. The Protocol is implemented on Tiny OS platform, tested using Tossim simulator and evaluated the Performance. SCUMG protocol is resilient to malicious code update by compromised nodes and provides security against various attacks.

Platform for Multiagent Application Development Incorporating Accurate Communications Modeling

Multiagent systems are widely recognized as a method of choice for realization of distributed time-critical applications for the smart grid. However, no general solutions have been proposed for the difficult task of system development and validation, ready for deployment, which would fully account for the underlying communication network performance. We propose a novel platform designed for this purpose, which integrates a standard multiagent development framework [Java Agent Development (JADE)] and an industry standard communications network simulator (OPNET modeler).

It was realized through generic extensions of the JADE framework to provide discrete event scheduling capabilities, while the OPNET modeler was extended to provide a generic method of associating the network nodes with agents running in JADE. The adopted method adheres to the high-level architecture standard. Importantly, applications developed using this platform may be deployed on the target system without manual modifications. A distributed protection application is presented and the performance is analyzed with respect to candidate agent behaviors and communication scenarios, demonstrating that the feasibility of the application critically depends on the choices made during its design and implementation.

Developing a coherent global view for post disaster situation awareness using opportunistic network

Situational awareness is a critical component in a post-disaster recovery operation for assessment of needs and identification of available resources at different parts of a disaster-affected area. This information, in turn, may help the relief agencies to appropriately coordinate, manage and channelize their resources. A major hindrance in developing such global situational awareness is the non-uniform interaction pattern of relief workers. Volunteers in a particular region have much better knowledge of the local situation than those belonging to regions further away. This information asymmetry leads to deviation in perceptions of volunteers working in different regions, thereby affecting the resource distribution process.

Thus, a unified global situational view of the entire disaster affected area is essential to bridge the perception gap of volunteers and to help them develop a common understanding of the actual scenario. In this paper, we propose a scheme for developing such a coherent global view of the post-disaster situation using local situational information in a smart-phone based delay tolerant peer-to-peer network environment.We focus on generating a comprehensive view which is consistent for all workers irrespective of their location or mobility. The proposed scheme takes into account the spatial locality and spatial regularity properties of human mobility and uses a concept of “opportunistic knowledge injection” to disseminate local situational knowledge to other remote areas without significantnetwork overhead. The effectiveness of the proposal is evaluated on the ONE simulator.

Rate, power and carrier-sense threshold coordinated management for high-density IEEE 802.11 networks

Nowadays, trying to obtain better coverage and performance, and allowed by the low-hardware prices, it is common to deploy a large number of IEEE 802.11 devices in offices, meeting rooms or auditoriums configuring the so called high-density networks. In such a scenario, the shared nature of the transmission medium causes interference problems. Some physical-layer- and link-layer-adaptation mechanisms to palliate those problems have been developed, however, most of them have not been independently implemented and assessed.

In this paper, we implement in a simulator some of the existent solutions, compare them in a simulation environment and show that, in some situations, the existing solutions can lead to a starvation problem. Finally, we propose a new mechanism that manages datarate, transmit power and carrier-sense threshold to ameliorate this problem.

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 simulatorand 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.

Comparison of heterogeneous network rain fade simulation tools: global integrated network SIMulator and MultiEXCELL

Two heterogeneous network simulation tools are compared and tested against measured data from terrestrial and Earth-space microwave links. Both global integrated network SIMulator (GINSIM) and MultiEXCELL are able to produce joint distributions of rain fade time-series for arbitrary networks of microwave telecommunications links. The tools are fundamentally different in that GINSIM has, as its input, time-series of composite rain rate maps produced by networks of meteorological radars and can produce time-series of joint rain fade.

MultiEXCELL uses the rain rate distribution as an input to constrain distributions of parameters of simulated rain cells. This study tests the simulators by comparing a range of annual fade statistics produced by simulation with data measured on experimental links. Link fade data were measured on two, Ka band, Earth-space links and a convergent 38 GHz terrestrial link near Chilbolton in southern England; and a further Earth-space link located in Dundee, Scotland. Both GINSIM and MultiEXCELL are shown to be able to predict joint fade distributions and diversity gain, for the satellite and terrestrial links, to useful accuracy. Differences in performance are analysed, leading to suggested development routes for both systems.

High gain Microstrip Antenna design for 2.4GHz WLAN application

IEEE 802.11x standard widely used in wireless local area network systems is called Wi-Fi as well. In this study high gain Microstrip Antenna (MA) design is presented for 2.4 GHz WLAN application. Simulations were made on parameters such as the geometry and size of antennas, type of dielectric material, the thickness of substrate for most appropriate designing of antenna.

For simulations, HFSS software which is a full wave and finite element based simulator was used. Total maximum gain of the designed antenna were obtained as 9.06 dB.

Impact of realistic simulation on the evaluation of mobileAd-hoc routing protocols

Today’s advanced simulators facilitate thorough studies on Vehicular Ad-hoc NETworks (VANETs). However the choice of the physical layer and the mobility models in such simulators is a crucial issue that greatly impacts the results. Realistic simulation of routing protocols in VANETs is still an open question. Indeed, only a few works address routing protocols comparison performed under realistic conditions. This paper compares common reactive, pro-active, hybrid and geographic routing protocols by using a simulation platform integrating a realistic physical layer and mobility models.

It also presents and analyzes several reactive protocols enhancements propositions dedicated to the VANETs context such as multi-path routing, but also protocols tuning which allows it to adapt faster. They have all received a lot of attention and are typically proposed to increase the reliability of data transmission. This paper study the behavior of each protocol in different situations and analized their advantages and drawbacks. Results presented in this paper gives an important explanation on the contradictory results found in similar works. Finally, our realistic simulations show that reactive protocols are the best suited for VANETs, and more especially the DYMO protocol.

Development of Real Time Protective Coordination Algorithm for HTS Power Cable

The electrical characteristics of the HTS power cable are dominantly dependent on the property of the HTS wire and cable geometry such as wire twist pitch, cable diameter, gap between the layers, etc. The quench occurs in HTS power cable caused by fault, the resistance appears, the current redistributed, the line impedance between the source and fault spot must be transiently changed, and mutual inductance value is directly affected.

It is very important to make sure that the protective coordination system is in real utility network. This paper presents a real time protective coordination algorithm for triad coaxial HTS power cable using symmetrical coordinate method and vector analysis under utility fault condition. The protective coordination algorithm is developed and evaluated by using the real time data acquisition system with real time digital simulator (RTDS).