Paper Title, Authors, Abstract (Issue 1, Volume 2, 2008)

Pages

Redundancy versus Video and Audio Human Perception
Michael Bank

Abstract: A proposal is put forward for an possible explanation of human perception algorithm. The main conclusion of different kinds of art perception examination is necessity of big part of signal redundancy. The article illustrates the meaning of redundancy versus human perception. It turned out, that there are common methods of redundancy creation in different kinds of art like painting, architecture, music and speech.
 

Noise Reduction and Simulation in Avalanche Photodiodes
F. Emami and M. Frdosiyan Tehrani

Abstract: One of the most important devices used in optical communication systems are Avalanche Photo Diodes (APDs). APDs are the proper devices in signal detection because of their wide bandwidth, low noise operation and sensitive detection respect to other detectors. In this paper, an overview of the noise specification is presented for them. Some structures such as thin multiplication layer APDs, impact ionization engineering, ultra-low noise APD with a centered-well multiplication region and some theories such as dead space multiplication theory (DSMT) and modified DSMT (MDSMT) are studied. The numerical simulation of nonlocal ionization and dead space effects in homojunction APDs are reviewed based on the history dependent multiplication theory (HDMT). Finally, we discussed the low noise CMOS APDs.
 

Radio Frequency Combination for TCP/IP Suite Protocol Improvement in 4G Mobile Internet Networks
Abdullah Gant, Xichun Li, Lina Yang, Omar Zakaria

Abstract: In this paper, we present our new proposed protocol to enhance the TCP/IP versatility as the main protocol for wireless data transmission. TCP/IP has shown its superiority in the selection of protocol for establishing wired networks. Unfortunately, its superiority cannot be extended to wireless networks. However, we believe that the integration of several types of networks would take place. The 4th Generation (4G) wireless mobile internet networks will merge the current existing cellular networks (i.e., CDMA2000, WCDMA and TD_SCDMA) and Wi-Fi networks (i.e., Wireless LAN) with the fixed internet to support wireless mobile internet. This integration would provide the same quality of service as fixed internet. Each of the networks has their own specified protocols, disparity frequency, and maximum data speed and cost characteristics. TCP/IP suite protocols were successful in web application of fixed internet, but exhibit limitation to work on the combined networks. Two research directions are available, which are replacement and improvement. Microsoft has issued a new protocol suite for replacement. In this paper, we propose a new protocol to improve TCP/IP suite protocols. This new protocol addresses the limitation of TCP/IP suite so that it can work on both cellular network and Wi-Fi network simultaneously; sending data requests through cellular network and getting reply from Wi-Fi network. Ns2 Java version (Java Network Simulator) was chosen to simulate the new protocol because of its feasibility. In this paper, we present the results and discussion of our simulation.
 

The Performances of the SSC Combiner Output Signal in the Presence of Nakagami-m Fading
Mihajlo Č. Stefanović, Dragana S. Krstić, Petar Nikolić, Srdjan Jovković, and Dušan M. Stefanović

Abstract: It is notable that level crossing rate, outage probability and average time of fade duration of the combiner output signal are very important system performances. In this paper the level crossing rate, outage probability and fade duration of the SSC combiner output signal in the presence of the Nakagami-m fading are determined. The results are shown graphically for different variance values, decision threshold values and fading parameters values.
 

Comparative Performance Study of ADMR and ODMRP in the context of Mobile Ad Hoc Networks and Wireless Sensor Networks
Radosveta Sokullu , Ozlem Karaca

Abstract: Mobile Ad Hoc networks (MANET) and Wireless Sensor Networks (WSNs) are two large groups of wireless networks that have well established application ranges. Despite the fact that they address very distinctive groups of devices and have clearly differentiated wireless interfaces, there are certain similarities which push scientists to look for adopting solutions already designed for existing wireless networks to WSNs. An example of this is the case with routing layer protocols. AODV, a unicast routing protocol, developed for MANETs, has proved to be applicable and was accepted by IEEE as the standard for the routing layer in Low Rate – Wireless Personal Area Networks (LR-WPAN). MANET-originated solutions, like multicast protocols, have also been initially designed in the context of IEEE 802.11 MAC layer protocol but have their applicability for WSNs not been studied so far. This paper investigates the feasibility of two popular MANET multicast protocols, ADMR and ODMRP over the IEEE 802.15.4 standard and provides a comprehensive study of the performance of these two protocols with different underlying physical and media access protocols. The protocols have been analyzed with ns-2 network simulator. It appears that even though both protocols are applicable in the selected scenarios, there are specifics in their performance in the context of WSNs which should not be neglected.
 

Study of Parameters Effect on the Performance of Precoding and Equalizer Sharing Systems
Mutamed Khatib, Mohd Fadzil. Ain, Farid Ghani, Syed Idris Syed Hassan

Abstract: This paper studies the effect of the block length and the channel impulse response on the performance of three block transmission systems. The main idea of the block transmission system is to transmit the data in blocks of certain length, and to use signal processing networks either in the transmitter or the receiver to eliminate the effect of the multipath channel. So, both the block length and the channel impulse response will play an important roll in the system performance. The first studied system moves all the signal processing operations from the receiver to the transmitter and leaves the receiver quite simple (pre-coding). The other two systems make some sharing of the signal processing between the transmitter and the receiver in different ratios to obtain some enhancement on the performance of the pre-coding system.
 

The Decision Reliability of MAP, Log-MAP, Max-Log-MAP and SOVA Algorithms for Turbo Codes
Lucian Andrei Perisoara, Rodica Stoian

Abstract: In this paper, we study the reliability of decisions of the MAP, Log-MAP, Max-Log-MAP and SOVA decoding algorithms for turbo codes, in terms of the a priori information, a posteriori information, extrinsic information and channel reliability. We also analyze how important an accurate estimate of channel reliability factor is to the good performances of the iterative turbo decoder. The simulations are made for parallel concatenation of two recursive systematic convolutional codes with a block interleaver at the transmitter, AWGN channel and iterative decoding with mentioned algorithms at the receiver.
 

Improving Life Time of Wireless Sensor Networks using Neural Network based Classification Techniques with Cooperative Routing
Sudhir G. Akojwar, Rajendra M. Patrikar

Abstract: Wireless Sensor Networks are design with energy constraint. Every attempt is being made to reduce the energy consumption of the wireless sensor node. Communication amongst nodes consumes the largest part of the energy. The paper focuses on use of classification techniques using neural network to reduce the data traffic from the node and there by reduce energy consumption. The sensor data is classified using ART1 Neural Network Model. Wireless sensor network populates distributed nodes. The cooperative routing protocol is designed for communication in a distributed environment. In a distributed environment, the data routing takes place in multiple hops and all the nodes take part in communication. This protocol has been designed for wireless sensor networks. This ensures uniform dissipation of energy for all the nodes in the whole network. Directed diffusion routing protocol is implemented to carry out performance comparison. The paper discusses classification technique using ART1 neural network models. The classified sensor data is communicated over the network using two different cases of routing: cooperative routing and diffusion routing. Ptolemy-II-Visual Sense is used for modeling and simulation of the sensor network. Lifetime improvement of the WSN is compared with and without classification using cooperative routing and diffusion routing.
 

An Energy Efficient Dynamic Clustering Scheme of MSN for Dynamic Skyline Queries
Young-Bok Cho, Yoon-Su Jeong, Sang-Ho Lee

Abstract: The wireless sensor network environment which is composed of a number of sensor nodes are extended to Ubiquitous application, and sink node are giving mobility and seamless data transmission, This paper is accounting for dynamic clustering focusing on the sink node, After choosing cluster headers, which share base station and data transmission dynamic clustering can transmit the data of the sink node. This paper defines the optimal hop counter and when a cluster is made prolong life time of the network by reducing the whole network energy efficiency. One of the Experiments show that clustering can be achieved within a single cluster by extending 6 hop at the maximum, and life time makes possible dynamic clustering when node remains more than 20% on average.
 

A Study of the Multi-Scale WOFDM Transmission in Time Variant Channels
Marius Oltean

Abstract: WOFDM (Wavelet-based Orthogonal Frequency Division Multiplexing) reshapes the multi-carrier transmission concept, by using wavelet carriers instead of OFDM’s complex exponentials. The modulator and the demodulator rely on the Discrete Wavelet Transform (DWT) computation. One crucial parameter of this transform is the number of iterations, tightly related to the time-scale nature of the wavelet transform. Practically, the number of DWT iterations coincides with the number of transmission scales used. The influence of this parameter on the WOFDM transmission performance is studied in this paper. The considered scenario refers to a flat, time variant Rayleigh fading channel. Our simulations show that, by increasing the number of transmission scales, the BER performance degrades. This result is explained by the fact that a small number of iterations keeps the duration of the transmitted symbols significantly shorter than the coherence time of the channel.
 

Security Issues in Wireless Sensor Networks
Zoran S. Bojkovic, Bojan M. Bakmaz, Miodrag R. Bakmaz

Abstract: This work deals with some security issues over wireless sensor networks (WSNs). A survey of recent trends in general security requirements, typical security treats, intrusion detection system, key distribution schemes and target localization is presented. In order to facilitate applications that require packet delivery from one or more senders to multiple receivers, provisioning security in group communications is pointed out as a critical and challenging goal. Presented issues are crucial for future implementation of WSN.
 

QoS Path Selection Mechanism in a Hybrid Access Wireless Scenario: A Distributed Approach using Mobile Agents
Emanuel Puschita, Tudor Palade

Abstract: The differentiated requirements of applications over this multitude of access networks need a mechanism for resource negotiation and management. The aim of the paper is to present an inter-domain end-to-end mechanism used for best path selection in a hybrid access WLAN-UMTS scenario, based on one-way delay estimation as the network parameter requested by the application and managed by mobile agents. Further, based on the obtained results, the paper proposed an extended mechanism using profiles, a set of aggregate parameters like bandwidth, delay, jitter, etc. The mechanism is called I-NAME (In-Network Autonomic Management Mechanism)and it is used for network resource reservation and management functions.
 

Frame Synchronization Symbols for an OFDM System
Ali A. Eyadeh

Abstract: In this paper, the problem of frame synchronization in orthogonal frequency division multiplexing (OFDM) system is considered. For an OFDM system, frame synchronization is achieved by forcing the receiver to start its FFT at the right time. One way in which this may be achieved is to precede the OFDM data with a special synchronization symbol. Two synchronization symbols are proposed to achieve frame synchronization for an OFDM, the wobbulation symbol and the Barker code. These symbols are evaluated in AWGN and two-ray multipath channels, and performances are compared in terms of the probability of correct synchronization.
 

Passive UHF RFID Tags in Arctic Environment
Jussi Nummela, Leena Ukkonen and Lauri Sydanheimo

Abstract: Radio frequency identification (RFID) systems are becoming more and more common in several industries. This enhances the requirements of tag antennas. Especially in logistics and supply chain management, which are major applications for RFID, the operating environment is expanding all the time. The identifiable items often travel in very cold, even arctic, environments. This can happen for example in geographically cold areas or in freezers with frozen food. In addition ice or snow can also be accrued on the tag surface. It is important that RFID tags work well in these extreme circumstances and the technology can be trusted. This paper studies the behaviour of passive UHF RFID tags in a cold (-20°C) environment. The effect of snow and ice on the surface of the tag was studied too. Both Gen1 and Gen2 antennas were tested and the results proved that passive UHF RFID tag antennas are usable in extreme conditions.
 

    Paper Title, Authors, Abstract (Issue 2, Volume 2, 2008)

Pages

Chaotic Sequences Implementations on Residue Number Spread Spectrum System
M. I. Youssef, M. Zahara, A. E. Emam, M. Abd ElGhany

Abstract: In this paper, the performance of chaotic code generators implemented in spread spectrum communication system is analyzed and compared to those using conventional pseudo random code generators as maximum length, gold code generators. Image is used as a data source and the histogram of the spreaded image is analyzed. Applicability of different types of generators are studied by examining their autocorrelation, cross-correlation performance and the bit error rate for the communication system is evaluated for various codes. Finally, a residue number arithmetic is added to the system; this system is evaluated and compared to that of non residue number system, measuring the histogram of the spreaded image and the probability of error for the system is measured.
 

A New Approach for Reduction of Redundancy Using Optimal Time Domain Sampling and Interpolation
S. Izadpanah, M. M. Ghanbarian, A. Kazerooni

Abstract: In this paper the authors consider a general method, based on time domain samples for spectral manipulation of the time-limited signals. In this direction, all of the needed formulas for practical periodic time-limited interpolation in two cases of low pass and band pass has been derived. The work begins with dividing an arbitrary signal in time domain into the time limited non-overlapping frames, then each frame is processed to find the effective maximum frequency or equivalently the minimum number of samples that satisfy some error criteria. To find the optimum sampling frequency we used periodic interpolation for resampling and reconstruction, and suitable zero finding of the discrete variable nonlinear equation by combination of the time and frequency computation to increase the speed of convergence.
 

A Modular Encoder Design Scheme for Turbo-encoded BPPM-OCDMA System
Muralidhar Kulkarni

Abstract: A Turbo-encoded Optical Code division Multiple Access(OCDMA) system has been simulated and an application specific design process has been proposed to implement a Turbo- encoded OCDMA modulated using Binary Pulse Position Modulation (BPPM) for transmission over optical fiber channels. The design process follows a modular approach and consists of four distinct modules RSC (Recursive Systematic Code) encoder, Pseudorandom Interleaver, Parallel to Serial Converter, BPPM circuit. A reference system has been designed for a frame size of 16 bits. Bit error rates were calculated for this reference design, assuming 10 simultaneous users using 5 iterations of the MAP decoding algorithm at various values of SNR for the two obtainable code rates (1/2; 1/3).
 

    Paper Title, Authors, Abstract (Issue 3, Volume 2, 2008)

Pages

Analyzing Distribution of Traffic Capacity
Dan Mancas, Ecaterina-Irina Manole, Nicolae-Iulian Enescu, Stefan Udristoiu

Abstract: In this paper, an evaluation of the network routing algorithms is made. In a real network, it is expected to find a mix of traffic capacities corresponding to different qualities of the video signal. This mix seems to be composed of a majority of smaller traffic capacities (poorer video signal) than higher traffic capacities. After that, the topology effect is presented. In matter of performance, topology and blocking problems are strongly related. As conclusions, solutions for the presented scenarios and also for other important scenarios are given.
 

Introducing Mobile Home Agents into the Distributed Authentication Protocol to Achieve Location Privacy in Mobile IPv6
Andrew Georgiades, Yuan Luo, Aboubaker Lasebae, Richard Comley

Abstract: Mobile IPv6 will be the basis for the fourth generation 4G networks which will completely revolutionize the way telecommunication devices operate. This paradigm shift will occur due to the sole use of packed switching networks. Mobile IPv6 utilizes binding updates as a route optimization to reduced triangle routing between the mobile node, the home agent and the correspondent node, allowing direct communication between the mobile node and the correspondent. However, direct communication between the nodes produces a range of security vulnerabilities, which the home agent avoided. This paper attempts to provide the advantages of using the home agent as an intermediary whilst reducing the latency of triangle routing. This can be achieved with the proposed use of a mobile home agent which essentially follows the mobile node as it moves between points of attachment providing location privacy and pseudo-direct communication, which can be incorporated into the distributed authentication protocol or be used as a stand alone solution.
 

Consumers' Behaviour Towards Internet Technology and Internet Marketing Tools
Noor R. Ab. Hamid

Abstract: The accessibility of the Internet and lower costs of doing transactions have given rise in customers bargaining power and intense global competition. Although the Internet has great potential for consumer value reports indicate that consumers vary in their levels of Internet adoption. Among the factors causing consumers lack of adoption is perceived risk associated with online transactions. This study explores the roles of perceived risk and user’s experience level in determining consumers’ adoption level. In addition, the effect of consumers’ level of experience on perceived risk is examined. Meanwhile, customers’ behaviours vary depending on several factors such as demographics, technology literacy and experience level and so forth which will then influence their assessment of service quality entailing brand loyalty. Based on the belief that marketing to well-defined segments of customers would improve the quality of services offered affording higher retention rates and at the same time increase firms’ profitability in the long run many companies have opted to implement customer relationship management (CRM) programs. Hence, this study also aims to understand the relationships between consumer’ behaviour and internet marketing programs. Findings from this study indicate that perceived risk does not influence the types of activities conducted on the Internet. In contrary, users’ experience level plays an important role in users’ level of Internet adoption. In addition, our findings also revealed that customers differ in their relationship decisions based on age, education and experience level. We discuss the implications to managers and future directions of research.
 

    Paper Title, Authors, Abstract (Issue 4, Volume 2, 2008)

Pages

Simulation of Distributed Multi-Pump Raman Amplifiers in Different Transmission Media
Mohsen Katebi Jahromi, Farzin Emami

Abstract: Three types of distributed Raman amplifiers; forward, backward and bidirectional pumping configurations are simulated and compared in this paper. Since the nonlinear effect of the fiber type is an important parameter in determining the simulation process, two types of fibers are used in our simulation; Z-fiber and dispersion shifted fiber (DSF). In each case the optimum parameters such as pump and signal powers, amplified spontaneous emission and noise figure are derived. We found that there is minimum total input power for backward case and there is minimum fluctuation in signal power along the fiber which leads to having the lowest ripple in signal to noise ratio. Indeed, DSFs have proper noise figure level and more uniform signal gain relative to the Z-fibers. Generally speaking, the fiber parameters have strong effects on the operation of multi-pump distributed Raman amplifiers, because of their nonlinearities.
 

On Optimizing the Planning of Multi-hop Wireless Networks using a Multi Objective Evolutionary Approach
D. Benyamina, N. Hallam, A. Hafid

Abstract: The optimization problem of planning Wireless Mesh Networks (WMNs) is a challenging problem that has been regarded as a cost-minimization problem, while other pertinent Quality of Service (QoS) criteria are modeled as constraints to be satisfied. We propose a novel approach that models, to some realistic extent, the problem of planning WMNs as a simultaneous optimization of deployment cost and network throughput under obvious network constraints. We propose two multi-objective models differing mainly in how the throughput objective is optimized. We tailor a nature-inspired meta-heuristic algorithm to solve the two models. The cost and the effectiveness of the planning solutions are two conflicting objectives which undermine each other. In such situations, the network planner would prefer a set of trade-off planning solutions at his disposal to choose from A comparative experimental study with different key-parameter settings on the two instance models is conducted to help network planner decide which planning optimization model to choose given their specific requirements and/or scenarios.
 

Secure and Energy Efficient Geocast Protocol for Sensor Networks with Misbehaving Nodes
Young-Chul Shim

Abstract: Geocast sends packets to all sensor nodes within a specified geographical region in order to gather data from sensor nodes in that region and is an important mechanism in sensor networks. In this paper we first introduce an energy-efficient geocast protocol. The proposed protocol builds a multicast tree connecting geocast nodes using an energy efficient broadcasting technique without making any restrictions on the shape of the geocast region. The proposed protocol reduces the energy consumption during the phase of sending commands to the sensor nodes in a geocast region. It also facilitates in-network data aggregation and, therefore, helps save energy during the data reporting phase. Then we modify the proposed protocol to include security mechanisms to protect the multicast tree and data being transferred over this tree not only from outside attackers but also compromised insider attackers.