Abstract

This paper investigates multi-carrier wire line communication system, focusing on the physical layer in discrete multi-tone DMT modulation system. DMT system has received much attention in modern communication technology and is finding attractive applications. The paper introduces and discusses the discrete wavelet transform DWT-based DMT. Extensive simulation has been applied to compare the performance of the new scheme with that of the traditional one. It has been found that the performance over AWGN channel can be enhanced also the transmission efficiency can be enlarged using DWT.

Abstract

Cantina is a content-based approach for detecting phishing web sites, based on the TF-IDF information retrieval algorithm. Phishing is a significant problem involving fraudulent email and web sites that trick unsuspecting users into revealing private information. In this paper discusses about the design and evaluation of several heuristics developed to reduce false positives. The experiments show that CANTINA is good at detecting phishing sites, correctly labeling approximately 95% of phishing sites using CANTINA.

Abstract

In wireless networks all nodes contending to access the medium are supposed to follow the rules of the Medium Access Control (MAC) layer. Wireless Medium Access Control (MAC) protocols such as IEEE 802.11 use a distributed contention resolution mechanism for sharing the wireless channel. The hosts competing for access to the channel are required to wait for a “back off” interval, randomly selected from a specified range, before initiating a transmission. Selfish nodes (or misbehaving nodes) tempt to manipulate their back off parameters to gain more access to the channel, and hence have higher performance than their fair share. Such selfish behavior in the MAC layer can have devastating side effects on the performance of Wireless Networks. Here, the problem of detection of node misbehavior in the MAC layer, with the objective to provide an optimum performance is being considered. This framework captures the presence of uncertainty of attacks and concentrates on the attacks that are most significant in terms of incurred performance losses. It also refers to the case of an intelligent attacker that can adapt its policy to avoid being detected.

Abstract

Most current research into computers and music focus on the development of media technology for delivering music to consumers (e.g., MP3 format, Internet search engines, and so on) our research focuses on the development of technology for musical creativity. This paper focuses on a particular technology that we are developing, which is based on Artificial Life (A-Life). The Artificial Life (A-life) approach to the development of software for music is a promising new development. However, the vast majority of existing A-life-based systems for musical composition employ Genetic Algorithms (GA) to produce musical melodies, rhythms, and so on. In these systems, music parameters are represented as genotypes and GA operators are applied on these representations to produce music according to given fitness criteria. We suggest that strictly GA-based methods suffer from the fact that musical composition should not be constrained by a definite set of fitness criteria. Moreover music is largely a cultural phenomenon driven by social pressure and this is cumbersome to model with standard GA alone. We propose an alternative approach to using strictly GA-based methods: the design of evolutionary algorithms that consider music as a cultural phenomenon whereby social pressure plays an important role in the development of musical conventions. This paper introduces three of algorithms of our own design: popularity, transformation and complexity algorithms, respectively. We also devised tools for extracting information about the behaviour of the algorithms in many different ways, providing the means to study the outcomes systematically.

Abstract

Several problems are required to be solved to apply the geographical routing protocol Greedy Perimeter Stateless Routing (GPSR) in wireless sensor networks. First, GPSR is designed with the assumption of links with bidirectional capability (symmetric links). This has to be modified in order to effectively use the energy available with the nodes. Second, due to dynamic nature of the sensor networks, data consistency can not be maintained when home nodes change. In this paper modified GPSR algorithm is proposed to attempt to solve these problems. The modification proposed is to make use of a Hierarchical Energy Tree (HET) constructed using the available energy in each node. Using this HET the paper suggests either a bidirectional link or unidirectional link with each node. The GPSR algorithm also makes use of a routing metric based on the energy in each node. Thus an Energy Aware GPSR algorithm using the HET (HETEA-GPSR) is proposed. The algorithm is implemented in ns2. Simulations are carried out to evaluate the performance of the proposed algorithm. The results show that the GPSR-EA performs well in terms of packet delivery, throughput and average energy consumption.

Abstract

This paper presents a research whose objective is to design and build up an intrusion detection and response model for Mobile Ad hoc NETworks (MANET). Mobile ad hoc networks are infrastructure-free, pervasive and ever-present in nature, without any centralized power. These unique MANET characteristics present more than a a small number of changes to secure them.

The proposed security model is called the Intrusion Detection and Response for Mobile Ad hoc Networks (IDRMAN). The objective of the proposed model is to provide a security framework that will become aware of various attacks and take appropriate measures to control the attack automatically. This model is based on identifying critical system parameters of a MANET that are affected by a variety of types of attacks, and incessantly monitoring the values of these parameters to detect and respond to attacks.

This paper explains the design and development of the detection framework and the response framework of the IDRMAN. The main aspects of the finding framework are data mining using CART to identify attack sensitive network parameters from the wealth of raw network data, statistical processing using six sigma to identify the thresholds for the attack sensitive parameters and quantification of the MANET node state through a measure called the Threat Index (TI) using fuzzy logic methodology. The main aspects of the response framework are intruder recognition and intruder separation through response action plans.

The effectiveness of the detection and response framework is mathematically analyzed using probability techniques. The detection framework is also evaluated by performance comparison experiments with related models, and through performance evaluation experiments from scalability perspective. Performance metrics used for assessing the detection feature of the proposed model are detection rate and false positive rate at different node mobility speed. Performance evaluation experiments for scalability are with respect to the size of the MANET, where more and more mobile nodes are added into the MANET at varied mobility speed. The results of both the mathematical analysis and the performance evaluation experiments are presented in this paper.

Abstract

Day by day the size of systems & application software is increasing, demanding huge memory. Movement of high volume information among various parts of computing system pays an important role as a factor to the overall power budget. Consumption of power has become an important issue for modern COMPUTING systems [1]. Suggested way is to reduce power consumption is to reduce a bus activities [2] Power consumption due to communication on system-level buses contributes a lot for overall power requirement. Various coding schemes have been proposed in literature to encode data to reduce the number of bus transition [3][4][5]. The paper aims at providing a framework for evaluation of one of the popular Bus encoding algorithms for 4-bit information flowing in computing system. Architectural exploration of a system design has been considered to focus on the power consumption estimation of memory communication as well as other components of system. Result shows that off chip busses consumes considerable amount of power. FVS / FV-MSB, BIC gives reduction of 50% reduction in I/O information movement average power dissipation and 25% reduction in I/O average power dissipation. We have also evaluated segmentation concept with analysis of all bits of channel. We find that Bus segmentation requires redefinition unlike the conventional one.

Abstract

The ATM Forum has chosen a rate-based scheme as an approach to congestion control for Available Bit Rate (ABR) services. So far, many rate-based schemes, such as Forward Explicit Congestion Notification (FECN), Backward Explicit Congestion Notification (BECN), and Proportional Rate Control Algorithm (PRCA), have been proposed. In FECN and BECN, which use negative feedback rate control, the over-all network congestion collapse may occur, if all notification cells in backward direction experience extreme congestion. The MSVDRS use positive feedback to solve the drawbacks of the FECN and BECN, but unfair distribution of available bandwidth among Virtual Connections (VCs) may occur. To resolve the problems of the existing  rate-based schemes, in this paper, we propose a new adaptive rate based congestion control scheme called the Multi-Source Virtual Dynamic Routing. The Scheme Mathematical analysis is given to demonstrate the stability of the closed-loop system so that a desired quality of service (QoS) can be guaranteed. The QoS is defined in terms of Cell Loss Ratio (CLR), transmission delay and buffer utilization. We derive design rules mathematically for selecting the parameters of the Multi Source Virtual Dynamic Routing (MSVDR) algorithm such that the desired performance is guaranteed during congestion and potential tradeoffs are shown. The performance of the proposed congestion control scheme is also evaluated in the presence of feed-back delays for robustness considerations. Finally, comparison studies are also included to show the effectiveness of the proposed method over conventional rate-based and thresh holding techniques during simulated congestion. We show that the MSVDR scheme can achieve good fairness performance among connection classes existing in the network.

Abstract

Since the early days of electronics, as advances in technology was taking place, the boundaries of both local and global communication began eroding, resulting in a world that is smaller and hence more easily accessible for the sharing of knowledge and information .the pioneering work by Bell and Marconi formed the corner stone of the information age that exists today and pavel the way for the future of telecommunication. The paper deals with the implementation of physical layer simulation reference system for a mobile system for a satellite-based wireless modem. The design is targeted into three modules —the transmitter, the channel considering AWGN noise and Rician fading and a receiver module following Matched filter and Bayesian Demodulation technique for the receiver designing.

Abstract

The power consumption is one of the most important design criteria in on-chip bus design. In VLSI design using deep sub micron technology, the bus energy reduction has become more and more important. As technology is scaling down, the increased interconnect wire aspect ratio and the reduced spacing between the individual wires within the bus result in increased cross coupling capacitances. They also increase cross talk noise and power dissipation in the data buses. In addition there is also a self-capacitance introduced between two adjacent data lines. We have developed an encoding algorithm that reduces the coupling transitions (1 to 0 or 0 to 1 state transition) and also the self-transitions in the data buses to minimize the energy dissipation. The technique requires 2 extra bits for sending coding information regardless of the bit width of the bus and does not assume anything about the nature of the data.