Simplified ordering for fixed-complexity sphere decoder

This paper proposes a simplified ordering algorithm for the fixed-complexity sphere decoder (FSD). The new algorithm is developed from the analysis of the ordering for FSD from a geometrical point of view. Computer simulation is used to assess the improvements in bit-error rate (BER) performances of MIMO systems using the FSD with the original and the simplified ordering. Simulation results show that the new ordering method can achieve nearly the same BER as the original ordering method but with much less complexity. Copyright © 2010 ACM.postprintThe 6th International Wireless Communications and Mobile Computing Conference (IWCMC 2010), Caen, France, 28 June-2 July 2010. In Proceedings of the 6th International Wireless Communications and Mobile Computing Conference, 2010, p. 804-80

Single Carrier Architecture for High Data Rate Wireless PAN Communications System

A 60 GHz wireless Gigabit Ethernet (G.E.) communication system is developed at IETR. As the 60 GHz radio link operates only in a single-room configuration, an additional Radio over Fibre (RoF) link is used to ensure the communications in all the rooms of a residential environment. The realized system covers 2 GHz bandwidth. Due to the hardware constraints, a symbol rate at 875 Mbps is attained using simple single carrier architecture. In the baseband (BB) processing block, an original byte/frame synchronization process is designed to provide a smaller value of the preamble missing detection and false alarm probabilities. Bit error rate (BER) measurements have been realized in a large gym for line-of-sight (LOS) conditions. A Tx-Rx distance greater than 30 meters was attained with low BER using high gain antennas and forward error correction RS (255, 239) coding.Comment: Design, Experimentation, Measurement, Performance; IWCMC '10, Caen : France (2010

Adaptive Engineering of an Embedded System, Engineered for use by Search and Rescue Canines

In Urban Search and Rescue (US&R) operations, canine teams are deployed to find live patients, and save lives. US&R may benefit from increased levels of situational awareness, through information made available through the use of embedded systems attached to the dogs. One of these is the Canine Pose Estimation (CPE) system. There are many challenges faced with such embedded systems including the engineering of such devices for use in disaster environments. Durability and wireless connectivity in areas with materials that inhibit wireless communications, the safety of the dog wearing the devices, and form factor must be accommodated. All of these factors must be weighed without compromising the accuracy of the application and the timely delivery of its data. This paper discusses the adaptive engineering process and how each of the unique challenges of emergency response embedded systems can be defined and overcome through effective design methods

Adaptive Neuro-Fuzzy Inference System for Dynamic Load Balancing in 3GPP LTE

ANFIS is applicable in modeling of key parameters when investigating the performance and functionality of wireless networks. The need to save both capital and operational expenditure in the management of wireless networks cannot be over-emphasized. Automation of network operations is a veritable means of achieving the necessary reduction in CAPEX and OPEX. To this end, next generations networks such WiMAX and 3GPP LTE and LTE-Advanced provide support for self-optimization, self-configuration and self-healing to minimize human-to-system interaction and hence reap the attendant benefits of automation. One of the most important optimization tasks is load balancing as it affects network operation right from planning through the lifespan of the network. Several methods for load balancing have been proposed. While some of them have a very buoyant theoretical basis, they are not practically implementable at the current state of technology. Furthermore, most of the techniques proposed employ iterative algorithm, which in itself is not computationally efficient. This paper proposes the use of soft computing, precisely adaptive neuro-fuzzy inference system for dynamic QoS-aware load balancing in 3GPP LTE. Three key performance indicators (i.e. number of satisfied user, virtual load and fairness distribution index) are used to adjust hysteresis task of load balancing

A Soft Computing Approach to Dynamic Load Balancing in 3GPP LTE

A major objective of the 3GPP LTE standard is the provision of high-speed data services. These services must be guaranteed under varying radio propagation conditions, to stochastically distributed mobile users. A necessity for determining and regulating the traffic load of eNodeBs naturally ensues. Load balancing is a self-optimization operation of self-organizing networks (SON). It aims at ensuring an equitable distribution of users in the network. This translates into better user satisfaction and a more efficient use of network resources. Several methods for load balancing have been proposed. Most of the algorithms are based on hard (traditional) computing which does not utilize the tolerance for precision of load balancing. This paper proposes the use of soft computing, precisely adaptive Neuro-fuzzy inference system (ANFIS) model for dynamic QoS aware load balancing in 3GPP LTE. The use of ANFIS offers learning capability of neural network and knowledge representation of fuzzy logic for a load balancing solution that is cost effective and closer to human intuitio

Boundary node selection algorithms in WSNs

Physical damage and/or node power exhaustion may lead to coverage holes in WSNs. Coverage holes can be directly detected by certain proximate nodes known as boundary nodes (B-nodes). Due to the sensor nodes' redundant deployment and autonomous fault detection, holes are surrounded by a margin of B-nodes (MB-nodes). If all B-nodes in the margin take part in the hole recovery processes, either by increasing their transmission power or by relocating towards region of interest (ROI), the probability of collision, interference, disconnection, and isolation may increase affecting the rest of the network's performance and QoS. Thus, distributed boundary node selection algorithms (BNS-Algorithms) are proposed to address these issues. BNS-algorithms allow B-nodes to self-select based on available 1-hop information extracted from nodes' simple geometrical and statistical features. Our results show that the performance of the proposed distributed BNS-algorithms approaches that of their centralized counterparts. © 2011 IEEE

Detection of denial-of-service attacks based on computer vision techniques

University of Technology, Sydney. Faculty of Engineering and Information Technology.A Denial-of-Service (DoS) attack is an intrusive attempt, which aims to force a designated resource (e.g., network bandwidth, processor time or memory) to be unavailable to its intended users. This attack is launched either by deliberately exploiting system vulnerabilities of a victim (e.g., a host, a router, or an entire network) or by flooding a victim with large volume of useless network traffic. Since 1990s, DoS attacks have emerged as a type of the most severe network intrusive behaviours and have posed serious threats to the infrastructures of computer networks and various network-based services. This thesis aims to provide an intelligent and effective solution for DoS attack detection. Unlike the related works based on machine learning and statistical analysis, this thesis suggests to treat network traffic records as images and to redefine the DoS attack detection problem as a computer vision task. To achieve the aforementioned objectives, this thesis first conducts a detailed literature review on the state of the art in DoS attack detection. Then, it analyses and chooses the most appropriate mechanisms for DoS attack detection. Afterwards, it designs a general system framework for DoS attack detection with respect to the chosen mechanisms. Furthermore, two Multivariate Correlation Analysis (MCA) approaches are proposed based on two techniques, namely Euclidean distance and triangle area. These two proposed MCA approaches provide accurate description for network traffic records and facilitate conversion of network traffic into the respective images. In addition, this thesis proposes a DoS attack detection system, in which the images of network traffic are served as the observed objects and the task of DoS attack detection is reformulated as a computer vision problem, namely image retrieval. This proposed DoS attack detection system applies a widely used dissimilarity measure, namely the Earth Mover’s Distance (EMD), to object classification. The EMD takes cross-bin matching into account and provides a more accurate evaluation on the dissimilarity between distributions than some other well-known dissimilarity measures, such as Minkowski-form distance Lp and X² statistics. The merits of the EMD facilitate the capability of our proposed system with effective detection. Last but not least, our intelligent and effective solutions, including the two proposed MCA approaches and the EMD-based DoS attack detection system, are evaluated using the KDD Cup 99 dataset. The evaluation results illustrate that our proposed MCA approaches provide accurate characterisation for network traffic, and the proposed detection system can detect unknown DoS attacks and outperforms two state-of-the-art approaches

Modeling the Energy Performance of Event-Driven Wireless Sensor Network by Using Static Sink and Mobile Sink

Wireless Sensor Networks (WSNs) designed for mission-critical applications suffer from limited sensing capacities, particularly fast energy depletion. Regarding this, mobile sinks can be used to balance the energy consumption in WSNs, but the frequent location updates of the mobile sinks can lead to data collisions and rapid energy consumption for some specific sensors. This paper explores an optimal barrier coverage based sensor deployment for event driven WSNs where a dual-sink model was designed to evaluate the energy performance of not only static sensors, but Static Sink (SS) and Mobile Sinks (MSs) simultaneously, based on parameters such as sensor transmission range r and the velocity of the mobile sink v, etc. Moreover, a MS mobility model was developed to enable SS and MSs to effectively collaborate, while achieving spatiotemporal energy performance efficiency by using the knowledge of the cumulative density function (cdf), Poisson process and M/G/1 queue. The simulation results verified that the improved energy performance of the whole network was demonstrated clearly and our eDSA algorithm is more efficient than the static-sink model, reducing energy consumption approximately in half. Moreover, we demonstrate that our results are robust to realistic sensing models and also validate the correctness of our results through extensive simulations

Efficiency metrics computing in combined sensor networks

This paper discusses the computer-aided design of combined networks for offices and building automation systems based on diverse wired and wireless standards. The design requirements for these networks are often contradictive and have to consider performance, energy and cost efficiency together. For usual office communication, quality of service is more important. In the wireless sensor networks, the energy efficiency is a critical requirement to ensure their long life, to reduce maintenance costs and to increase reliability. The network optimization problem has been solved under considering of overall-costs as objective and quality of service including throughput, delay, packet losses etc. with energy efficiency as required constraints. This can be achieved by a combination of different planning methods like placement of wired and wireless nodes, tracing of cabling systems, energy-efficient sensor management and event-based sampling. A successful application of these methods requires a combined harmonized design at different levels of the networks. This paper aims to demonstrate how these methods are realized in the network planning. These tools provide optimized wired and wireless topologies under considering of costs, distances, transmitted power, frequencies, propagation environments and obstacles given in computer-aided design compatible formats