Engineering Commons^™

Source Separation Approach To Video Quality Prediction In Computer Networks, Ruairí De Fréin

Articles

Time-varying loads introduce errors in the estimated model parameters of service-level predictors in Computer Networks. A load-adjusted modification of a traditional unadjusted service-level predictor is contributed, based on Source Separation (SS). It mitigates these errors and improves service-quality predictions for Video-on-Demand (VoD) by :6 to 2dB.

Monitoring Voip Speech Quality For Chopped And Clipped Speech, Andrew Hines, Jan Skoglund, Anil C. Kokaram, Naomi Harte

Articles

No abstract provided.

Towards A Framework For Modelling Multimedia Conferencing Calls In The Next Generation Network, Gavin Byrne, Declan Barber

The ITB Journal

This paper is concerned with the creation of a multiparty multimedia conferencing application which can be used in Next Generation Networks. It begins by suggesting ways in which conferencing can be modeled with a focus on separating signaling and media transfer functionality. Enabling technologies which could support the modeling framework derived and which are compatible with Next Generation Network (NGN) principles are reviewed. Finally, a design and implementation for a simple multimedia conferencing application are described.

Embedded Systems In A Mobile Distributed Ip Network, Conor Gildea, Declan Barber

The ITB Journal

This paper describes an approach to the internetworking of mobile IP sensor nodes in a converged network environment. This preliminary investigation of sensory network models is driven by a joint applied research project between ITB and Teagasc (Grange) which seeks to establish the feasibility of the real-time remote monitoring of animal welfare while in transit between Ireland, Europe and the Middle East. The paper examines traditional system architectures, messaging paradigms and protocols with a view to establishing how the trend towards convergence in telecommunications and the emergence of new Internet Protocols could support the creation of new modes of operation …

Unified Messaging Systems: An Evolutionary Overview, Declan Barber

The ITB Journal

Over the last decade, the widespread demand and use of the internet has changed the direction of the telecommunications industry as it was recognised that the internet could be used as an inexpensive way to handle not only data but also voice communications. This convergence of traditional voice and data technologies towards an IP-based open architecture has been paralleled by a convergence of the internet and mobile communications. As a result of these convergences, unified messaging has emerged as a technically viable service. Integrated messaging services that offer partial unification of different message types are already in the marketplace. This …

An Xml Framework For The Structured Data Exchange Between Medical Devices, Ulrich Neuhaus, Paul Walsh

The ITB Journal

This paper describes an XML framework for the exchange of data between medical devices and software systems. XML technologies offer an extensible data format, which is easy to both create and process and simplifies the exchange of data. Different XML standards are defined within the framework in order to provide a practical solution for both device manufacturers and software developers. The structure and benefits of XML documents are discussed and an XML framework for ophthalmology is described.

Longer Than A Telephone Wire - Voice Firewalls To Counter Ubiquitous Lie Detection, Carl Reynolds, Matt Smith, Mark Woodman

The ITB Journal

Mobile computing and communication devices are open to surreptitious privacy attacks using emotion detection techniques; largely utilising work carried out in the area of voice stress analysis (VSA). This paper extends some work in the area of removing emotion cues in the voice, specifically focusing on lie detection and presents the results of a pilot study indicating that the use of mobile phones in situations of stress is common and that awareness of VSA is low. Existing strategies for the removal or modification of emotion cues, based on models of synthesis are considered and weaknesses are identified.

Globalcom, Declan Barber, Conor Gildea, Gavin Byrne

The ITB Journal

The objective of this developed application is to provide a company with a means of communicating with its employees no matter where they are physically located and what communication resources they may have at any particular time. The core focus of this application is to provide a Unified Messaging System using synchronous and asynchronous forms.

The Role Of Cryptography In Security For Electronic Commerce, Ann Murphy, David Murphy

The ITB Journal

Many businesses and consumers are wary of conducting business over the Internet due to a perceived lack of security. Electronic business is subject to a variety of threats such as unauthorised access, misappropriation, alteration and destruction of both data and systems. This paper explores the major security concerns of businesses and users and describes the cryptographic techniques used to reduce such risks.

Xml For Business To Business Data Exchange, Geraldine Gray, David Kerwick

The ITB Journal

This paper examines to use of XML for business to business data exchange. Starting with creating an XML document from an existing data source and transmitting that document, we explain some of the supporting standards for XML which facilitate automated processing and transformation of an XML document. Finally we look at the advantages of using XML, and why it is expected to revolutionise electronic data interchange.

Measuring And Monitoring Speech Quality For Voice Over Ip With Polqa, Visqol And P.563, Andrew Hines, Eoin Gillen, Naomi Harte

Conference papers

There are many types of degradation which can occur in Voice over IP (VoIP) calls. Of interest in this work are degradations which occur independently of the codec, hardware or network in use. Specifically, their effect on the subjective and objec- tive quality of the speech is examined. Since no dataset suit- able for this purpose exists, a new dataset (TCD-VoIP) has been created and has been made publicly available. The dataset con- tains speech clips suffering from a range of common call qual- ity degradations, as well as a set of subjective opinion scores on the clips from 24 …

An Adaptive Packet Aggregation Algorithm (Aam) For Wireless Networks, Jianhua Deng

Doctoral

Packet aggregation algorithms are used to improve the throughput performance by combining a number of packets into a single transmission unit in order to reduce the overhead associated with each transmission within a packet-based communications network. However, the throughput improvement is also accompanied by a delay increase. The biggest drawback of a significant number of the proposed packet aggregation algorithms is that they tend to only optimize a single metric, i.e. either to maximize throughput or to minimize delay. They do not permit an optimal trade-off between maximizing throughput and minimizing delay. Therefore, these algorithms cannot achieve the optimal network …

An Autonomous Channel Selection Algorithm For Wlans, Fuhu Deng

Doctoral

IEEE 802.11 wireless devices need to select a channel in order to transmit their packets. However, as a result of the contention-based nature of the IEEE 802.11 CSMA/CA MAC mechanism, the capacity experienced by a station is not fixed. When a station cannot win a sufficient number of transmission opportunities to satisfy its traffic load, it will become saturated. If the saturation condition persists, more and more packets are stored in the transmit queue and congestion occurs. Congestion leads to high packet delay and may ultimately result in catastrophic packet loss when the transmit queue’s capacity is exceeded. In this …

Adaptive Ofdm For Wireless Interconnect In Confined Enclosures, Vit Sipal, Javier Gelabert, Christopher J. Stevens, Ben Allen, David Edwards

Articles

This letter considers and recommends OFDM with adaptive subcarrier modulation as a suitable candidate for wireless UWB communication in computer chassis. A rigorous measurement campaign studies the guaranteed spectral efficiency. It concludes that enhancement of the existing WiMedia OFDM systems with a bandwidth of 528 MHz in order to support adaptive OFDM would enable data-rates above 1 Gbps over short ranges, i.e. the spectral efficiency would be doubled. Moreover, the guaranteed spectral efficiency is shown to increase with bandwidth, i.e. the guaranteed data-rate increases better than linearly with bandwidth.

A Wireless And Digital Electrode Bus Topology For Biopotential Measurement, Mark Nolan, Edward Burke, Eugene Coyle

Conference Papers

The conventional biopotential measurement configuration utilises long lead wires which connect measuring electrodes to signal conditioning circuitry. The majority of bioelectric signals that are measured from the human body have a tiny signal amplitude (5µV-5mV range) and thus any interference that is induced on the lead wires can have a detrimental effect on the original signal. In this paper, we present an alternative configuration, in which digitisation occurs on the electrode, potentially providing enhanced signal measurement as well as significant benefits in terms of the simplification of the physical interconnections between electrodes. Multiple electrodes are combined to form a digital …

On The Applications Of Deterministic Chaos For Encrypting Data On The Cloud, Jonathan Blackledge, Nikolai Ptitsyn

Conference papers

Cloud computing is expected to grow considerably in the future because it has so many advantages with regard to sale and cost, change management, next generation architectures, choice and agility. However, one of the principal concerns for users of the Cloud is lack of control and above all, data security. This paper considers an approach to encrypting information before it is ‘placed’ on the Cloud where each user has access to their own encryption algorithm, an algorithm that is based on a set of iterated function systems that outputs a chaotic number stream, designed to produce a cryptographically secure cipher. …

Application Of Stochastic Diffusion For Hiding High Fidelity Encrypted Images, Jonathan Blackledge, Abdulrahman Al-Rawi

Articles

Cryptography coupled with information hiding has received increased attention in recent years and has become a major research theme because of the importance of protecting encrypted information in any Electronic Data Interchange system in a way that is both discrete and covert. One of the essential limitations in any cryptography system is that the encrypted data provides an indication on its importance which arouses suspicion and makes it vulnerable to attack. Information hiding of Steganography provides a potential solution to this issue by making the data imperceptible, the security of the hidden information being a threat only if its existence …

A Cross-Layer Modification To The Dsr Routing Protocol In Wireless Mesh Networks, Mustafa Ramadhan

Doctoral

A cross-layer modification to the DSR routing protocol that finds high throughput paths in WMNs has been introduced in this work. The Access Efficiency Factor (AEF) has been introduced in this modification as a local congestion avoidance metric for the DSR routing mechanism as an alternative to the hop count (Hc) metric. In this modification, the selected path is identified by finding a path with the highest minimum AEF (max_min_AEF) value. The basis of this study is to compare the performance of the Hc and max_min_AEF as routing metrics for the DSR protocol in WMNs using the OPNET modeler. Performance …

E-Fraud Prevention Based On The Self-Authentication Of E-Documents, Jonathan Blackledge, Eugene Coyle

Conference papers

We consider a method for preventing e-Fraud in which a binary image is encrypted with a floating point cipher using a convolution operation and the output quantized into a 1-bit array generating a binary image ciphertext. The output is then ‘embedded’ in a host image to hide the encrypted information. Embedding is undertaken either in the lowest 1-bit layer or multiple 1-bit layers. Decryption is accomplished by: (i) extracting the binary image from the host image; (ii) correlating the result with the original cipher. In principle, any cipher generator can be used for this purpose and the method has been …

On The Applications Of Deterministic Chaos For Encrypting Data On The Cloud, Jonathan Blackledge, Nikolai Ptitsyn

Conference papers

Cloud computing is expected to grow considerably in the future because it has so many advantages with regard to sale and cost, change management, next generation architectures, choice and agility. However, one of the principal concerns for users of the Cloud is lack of control and above all, data security. This paper considers an approach to encrypting information before it is ‘place’ on the Cloud where each user has access to their own encryption algorithm, an algorithm that is based on a set of Iterative Function Systems that outputs a chaotic number stream, designed to produce a cryptographically secure cipher. …

Egoviz – A Mobile Based Spatial Interaction System, Keith Gardiner, Junjun Yin, James Carswell

Articles

This paper describes research carried out in the area of mobile spatial interaction and the development of a mobile (i.e. on-device) version of a simulated web-based 2D directional query processor. The TellMe application integrates location (from GPS, GSM, WiFi) and orientation (from digital compass/tilt sensors) sensing technologies into an enhanced spatial query processing module capable of exploiting a mobile device’s position and orientation for querying real-world 3D spatial datasets. This paper outlines the technique used to combine these technologies and the architecture needed to deploy them on a sensor enabled smartphone (i.e. Nokia 6210 Navigator). With all these sensor technologies …

A Bandwidth Aware Modification To The Dsr Routing Protocol For Wireless Mesh Networks, Mustafa Ramadhan, Mark Davis

Conference papers

This work proposes a bandwidth aware cross-layer modification to the DSR routing protocol. We include the Access Efficiency Factor (AEF) parameter in addition to the hop-count in the routing discovery mechanism. AEF is a measure to the local availability of bandwidth at a node. Employing the AEF as a metric in the routing discovery mechanism attempts to avoid routing through a congested area in the network. In this modification, we impose a limit on the hop-count in order to control the delay time in the network. The path selection procedure operates by finding a path with the highest minimum AEF …

Self-Authentication Of Audio Signals By Chirp Coding, Jonathan Blackledge, Eugene Coyle

Conference papers

This paper discusses a new approach to ‘watermarking’ digital signals using linear frequency modulated or ‘chirp’ coding. The principles underlying this approach are based on the use of a matched filter to provide a reconstruction of a chirped code that is uniquely robust in the case of signals with very low signal-to-noise ratios. Chirp coding for authenticating data is generic in the sense that it can be used for a range of data types and applications (the authentication of speech and audio signals, for example). The theoretical and computational aspects of the matched filter and the properties of a chirp …

A Covert Encryption Method For Applications In Electronic Data Interchange, Jonathan Blackledge, Dmitry Dubovitskiy

Articles

A principal weakness of all encryption systems is that the output data can be ‘seen’ to be encrypted. In other words, encrypted data provides a ‘flag’ on the potential value of the information that has been encrypted. In this paper, we provide a new approach to ‘hiding’ encrypted data in a digital image.

In conventional (symmetric) encryption, the plaintext is usually represented as a binary stream and encrypted using an XOR type operation with a binary cipher. The algorithm used is ideally designed to: (i) generate a maximum entropy cipher so that there is no bias with regard to any …

Optimisation Of Multicast Routing In Wireless Mesh Networks, Brian Keegan, Karol Kowalik, Mark Davis

Conference papers

In recent years Wireless Mesh Networks have been deployed and grown in popularity in many metropolitan areas. The deployment of such networks has allowed clients to gain access to publicly available broadband networks. The implementation of wireless mesh networks requires that backhaul services (traditionally carried by wired networks) be maintained via wireless mesh points. Because of their structure, wireless mesh networks provide an excellent means for targeting a large group of end users or simply to relay data. This may be achieved by means of broadcasting or more specifically multicasting. The lack of standards and support for multicasting over wireless …

Antennas For Portable Communications In The Uwb And Gps Spectra., Giuseppe Ruvio

Doctoral

The thesis describes a study of antennas for solutions in emerging systems. An account of the fundamental principles of these antennas is given together with an outline of the basic electromagnetic theory on which the designs are based. While the main focus is on antennas for Ultra Wideband (UWB) systems, some additional work was carried out on enhancing performance of circularly polarised antennas for satellite navigation systems. The study focussed on the design of highly efficient broadband antennas with particular requirements for size compactness, gain stability, phase-linearity, and the use of low-cost materials. These requirements are particularly important for UWB …

Technology-Aided Participative Methods In Environmental Assessment: An International Perspective, Ainhoa Gonzalez, Alan Gilmer, Ronan Foley, John Sweeney, John Fry

Articles

Provisions for citizen involvement in the assessment of potential environmental effects of certain plans, programmes and projects are present in current legislation. An international survey revealed that public participation is common practice in European and some other countries worldwide. However, a number of issues are observed to affect public involvement in EIA/SEA processes and expert opinion differs when evaluating the effectiveness of existing participative methods. Results suggest that technology-aided methods can improve traditional participation processes. In particular, GIS has the potential to increase community knowledge and enhance involvement by communicating information more effectively. Variable accessibility to technology and data quality …

The Effects Of Contention Among Stations On Video Streaming Applications Over Wireless Local Area Networks: An Experimental Approach, Nicola Cranley, Tanmoy Debnath

Conference papers

Multimedia streaming applications have a large impact on the resource requirements of the WLAN. There are many variables involved in video streaming, such as the video content being streamed, how the video is encoded and how it is sent. This makes the role of radio resource management and the provision of QoS guarantees extremely difficult. For video streaming applications, packet loss and packets dropped due to excessive delay are the primary factors that affect the received video quality. In this paper, we experimentally analyse the effects of contention on the performance of video streaming applications with a given delay constraint …

Investigating Text Message Classification Using Case-Based Reasoning, Matt Healy

Masters

Text classification is the categorization of text into a predefined set of categories. Text classification is becoming increasingly important given the large volume of text stored electronically e.g. email, digital libraries and the World Wide Web (WWW). These documents represent a massive amount of information that can be accessed easily. To gain benefit from using this information requires organisation. One way of organising it automatically is to use text classification. A number of well known machine learning techniques have been used in text classification including Naïve Bayes, Support Vector Machines and Decision Trees, and the less commonly used are k-Nearest …

An Experimental Analysis Of The Call Capacity Of Ieee 802.11b Wireless Local Area Networks For Voip Telephony, Brian Keegan, Mark Davis

Conference papers

In this paper we present the results from an experimental study of the call capacity of an IEEE 802.11b network when using VoIP telephony. Experiments include increasing the number of VoIP users in a wireless test-bed and increasing the level of background traffic until network saturation occurs. The experiments allow us to perform an analysis of the access point (AP) buffer dynamics. Results show that the network is capable of supporting up to 16 VoIP stations (STAs). Due to the operation of the IEEE 802.11 medium access control (MAC) mechanism, the AP acts as a bottleneck for all traffic destined …