Pubs:2007

<bibtex> @inproceedings{137, author={Kevin Collins ; Gabriel Miro Muntean}, title={TraffCon: An Intelligent Traffic Control System for Wireless Vehicular Networks}, booktitle={IET CIICT}, year={2007}, abstract={Traffic Congestion is a very serious problem which is becoming ever worse as the growth in the number of cars on the road significantly outpaces the provision of road capacity. This paper presents TraffCon, a novel Traffic Management System (TMS) for Wireless Vehicular Networks that combats this problem by seeking to optimize the usage of the existing road capacity. It also outlines an architecture which includes a novel server-side decision making module, that enables the dissemination of instructions to vehicles; if followed these result in optimal road usage. }, keywords={Wireless Networks,Traffic Management, Road Vehicles, Driver Instruction}, } </bibtex> <bibtex> @inbook{159, author={Moebs, S. and Weibelzahl, S.}, title={Blended Learning: Towards a Mix for SMEs - Stakeholders and their Priorities}, publisher={Blended Learning}, year={2007}, pages={162-173},

abstract={

While blended learning seems to be quite suitable for small and medium sized enterprises (SMEs), current uptake of this learning method is low.
In this paper we propose a research design to examine the requirements for blended learning in SMEs. It is based on a three-round ranking-type Delphi
study. Participants for the panels were carefully selected. Our method takes into account that the area and the term of blended learning are discussed in very
different, partially contradicting connotations. For this purpose, we first provide the background of the initial research question and describe our research design.
Next, we present preliminary results of the Delphi study and the steps in preparation of round 2. Participants were selected for the online-Delphi and grouped into panels of SME learners, trainers and providers of e-learning as well as learners from large companies as a control group for the SME learners.

},

keywords={blended learning, SME, learning technology, Delphi study, Requirements}, pdf={wbl2007_BL4SMEs.pdf}, } </bibtex> <bibtex> @inproceedings{185, author={Seung-Bum Lee;Gabriel-Miro Muntean;Alan F. Smeaton}, title={Cost-oriented Context and Content Data Pair Delivery in Smart PIN}, booktitle={China-Ireland International Conference on Information and Communications Technologies}, year={2007}, pages={97-204}, abstract={With evolutions of wireless technologies and advances in mobile services, ubiquitous devices have huge acquired and storing data which requires metadata for user to handle easily. For this purpose, this paper introduces Smart PIN - a novel performance and cost-oriented, context-aware personal information network. Smart PIN architecture includes network components, service components and management components. At the service components, there should be consideration for service discovery, service composition, data replication management and data pair transfer. Among these issues, this paper proposes a novel scheme for efficient delivery of context and content data based on pull and push scheme controlling logical and physical cost function.}, keywords={Context-awareness, Data replication, Cost-effectiveness, Wireless PAN}, } </bibtex> <bibtex> @inproceedings{216, author={S. Murphy, M. Atiquzzaman, J. Fitzpatrick, J. Murphy}, title={Terminal-oriented solutions for seamless service delivery via heterogeneous radio access networks (Invited Paper)}, booktitle={Sarnoff Symposium 2007}, year={2007}, abstract={In this paper, options for providing seamless service delivery to mobile terminals via heterogeneous radio access networks are considered. Despite its current popularity, the Mobile IP solution for mobility management of mobile hosts is discounted due to problems associated with introducing the required network infrastructure and poor handover performance. Rather, the solution described here comprises of a number of key technologies working together. More specifically, the paper argues that the most appropriate solution comprises of the following: adaptive applications, an abstraction layer between application and transport layer, an intelligent transport layer with multi-homing and multi-path support and a means to obtain current state information about each of the available access networks. While work has been ongoing on each of these individual components little has been done to address how they can all be integrated and consider how they may perform in the context of different radio access technologies, potentially operated by different entities. This paper attempts to address some of these issues.}, keywords={Heterogeneous wireless access networks, Handover, Mobile Networking}, } </bibtex> <bibtex> @inproceedings{217, author={J. Fitzpatrick, S. Murphy, M. Atiquzzaman, J. Murphy}, title={Evaluation of VoIP in a Mobile Environment using an SCTP based Handoff Mechanism}, booktitle={IST Mobile Summit}, year={2007}, abstract={In parallel with the growth of VoIP services, a large number of manufacturers have begun to develop multimode devices capable of connecting to multiple wireless access networks simultaneously. These multimode terminals have, in principle, the capability to support seamless handover between different radio access networks. One handover solution that utilises the IP diversity which these multimode devices can deliver is SIGMA. SIGMA is a promising end-to-end transport layer handover solution based on SCTP. The objective of this paper is to investigate if SIGMA is capable of providing seamless handover of VoIP calls without degradation in voice quality. To achieve this, we developed a Linux based testbed on which we implemented a VoIP client and server using SIGMA handoff . Each voice call uses the G.711 voice codec over RTP. PR-SCTP is used in place of the traditional UDP as the transport layer protocol. SIGMA based handover was used during full duplex voice calls between the client and server. The ITU-T E-Model has been used to calculate the voice quality during the handover. Results show that SIGMA can be used as a seamless handover mechanism for VoIP without any impact on voice quality.}, keywords={SCTP, VoIP, SIGMA, Seamless Handover}, } </bibtex> <bibtex> @inproceedings{233, author={Odd Inge Hillestad; Andrew Perkis; Vasken Genc; Sean Murphy; John Murphy}, title={Adaptive H.264/MPEG-4 SVC video over IEEE 802.16 Broadband Wireless Networks}, booktitle={Packet Video}, year={2007}, abstract={In this paper we present a solution for delivering streaming video-on-demand to subscribers via an 802.16 broadband wireless access network. The solution leverages the forthcoming H.264/AVC Scalable Video Coding (SVC) scheme and a mechanism to perform rate adaptation based on monitoring changes to the amount of flow traffic in the network at any time. A simulation-based approach is used to determine how the system performs in a rural deployment. Results show that the scheme provides high utilization of the wireless access system, at over 96%. Further, it maintains smooth transmission rate for the video applications, and ensures that no interruptions in continuous video playback occur during the streaming session. Lastly, a comparison with single-layer H.264/AVC is performed, showing how the proposed solution performs better with respect to both system utilization and the fact that no clients suffer interruptions in continuous playback.}, keywords={IEEE 802.16, video streaming, scalable video coding}, } </bibtex> <bibtex> @inproceedings{322, author={Ormond,O.;Murphy,J.;Muntean,G.}, title={Dynamic Network Selection in Wireless LAN/MAN Heterogenous Networks}, booktitle={Mobile WiMAX:Toward Broadband Wireless Metropolitan Area Networks}, year={2007}, abstract={In future generations of wireless networks, it is expected that different users with various multi-homed personal wireless devices will have the option of accessing their desired services via different available radio access networks. Given the variability of the radio environment properties and user mobility, the availability and characteristics of an access network will change in time and are highly dependent on location. As a result, dynamic reselection of the access network will be a necessary part of the mobility management mechanism (which maintains the session connectivity as the user moves and/or the available access characteristics change). In their selection of a radio access network customers will consider cost and perceptive quality preferences for the current application and will rely on intelligent network selection decision strategies to aid or automate their choice. These dynamic selection strategies will need to take into account different dynamic, and sometimes conflicting, metrics}, keywords={Wireless Communication}, pdf={dynamic network.pdf}, } </bibtex> <bibtex> @inproceedings{323, author={Carrig,B.;Denieffe,D.;Murphy,J.}, title={A Non-Elevated Scheduling Solution for First Person Shooter Games in IEEE 802.11 Networks}, booktitle={IEEE Globecom 2007}, year={2007}, abstract={First Person Shooter (FPS) games are a popular online gaming genre played predominately over wired networks. FPS games are highly interactive and have stringent delay requirements. However, the explosive growth in wireless LAN (WLAN) deployment has seen an increase in the use of such networks for gaming purposes. The varied performance of the IEEE 802.11 MAC Distributed Coordination Function (DCF) has tended to make WLANs unsuitable for FPS games. The IEEE 802.11e standard introduces Quality of Service (QoS) mechanisms including Enhanced Distributed Channel Access (EDCA) allowing prioritization of competing flows. Using the NS- 2 simulator, we evaluate the capability of 802.11g and 802.11e WLANs to support Quake IV games traffic in the presence of web traffic. We compare the results achieved using EDCA with those achieved by a non-elevated differentiated services scheduler known as Best Effort with Loss Trade-off (BELT). We find that the BELT scheduler compares favorably with EDCA in this context.}, keywords={Online Gaming,LAN,QOS}, pdf={non elevated.pdf}, } </bibtex> <bibtex> @inproceedings{324, author={Carrig,B.;Denieffe,D.;Murphy,J.}, title={A Congestion-only Charging Mechanism for Multiplayer Gaming in Diffrentiated Service Networks}, booktitle={IEEE Globecom 2007}, year={2007}, abstract={In networks based on the Di®erentiated Services (Di®Serv) architecture, users may be presented the opportunity to choose their Assured Forwarding (AF) class. Users will attempt to maximize their Consumer Surplus (CS) in such an environment. They can increase their CS by choosing the lowest cost AF class that satis¯es their Quality of Service (QoS) requirements. Previously the authors have proposed an algorithm known as Consumer Surplus Maximization (CSM) [2]. Although this algorithm improves CS for users, widespread adoption of the algorithm can provoke network instability. If many users switch classes at once, degradation on one AF class can easily propagate. The likelihood of such an occurrence can be reduced by replacing ¯xed per- byte or per-packet charges associated with individual AF classes with a lightweight Congestion-only Charging (CoC) pricing mechanism. An additional charge is only applied to packets that receive discernible bene¯t from belonging to a particular class. We present simulation results from a networking scenario where users connect across a single Di®Serv domain to engage in a multiplayer First Person Shooter (FPS) game.}, keywords={Pricing, Quality of Service, Di®Serv}, pdf={congestion only.pdf}, } </bibtex> <bibtex> @inproceedings{325, author={Murphy,L.;Noonan,J.;Perry,P.;Murphy,J.}, title={An Application-quality based Mobility Management Scheme}, booktitle={9th International Conference on Mobile & Wireless Communication Networks}, year={2007}, abstract={Experimental results are presented for end-point controlled handover of a stream of voice-like packet data traffic between two independent wireless networks. The handover was achieved by using a version of the Stream Control Transmission Protocol (SCTP) that had been modified to monitor link quality and switch the primary connection to the “best” quality link available, where quality is evaluated in terms of application performance. The results clearly show that mobility management based solely on received signal strength is not suitable for wireless systems with contention-based access policies such as WiFi.}, keywords={Mobile Communication, Network Testing, Packet Radio, Wide area networks, Wireless LAN, Handover, VoIP, Call Quality}, pdf={application-quality.pdf}, } </bibtex> <bibtex> @inproceedings{326, author={Carrig,B.;Denieffe,D.;Murphy,J.}, title={Supporting First Person Shooter Games in Wireless Local Area Networks}, booktitle={IEEE 18th International Symposium on Personal,Indoor & Mobile Radio Communications}, year={2007}, abstract={First Person Shooter (FPS) games are a popular online gaming genre played predominately over wired networks. FPS games are highly interactive and have stringent delay requirements. However, the explosive growth in wireless LAN (WLAN) deployment has seen an increase in the use of such networks for gaming purposes. The varied performance of the IEEE 802.11 MAC Distributed Coordination Function (DCF) has tended to make WLANs unsuitable for FPS games. The IEEE 802.11e standard introduces Quality of Service (QoS) mechanisms including Enhanced Distributed Channel Access (EDCA) allowing prioritization of competing flows. Using the NS-2 simulator, we evaluate the capability of 802.11g and 802.11e WLANs to support Quake IV games traffic in the presence of web traffic. We compare the results achieved using EDCA with those achieved by a non-elevated differentiated services scheduler known as Best Effort with Loss Trade-off (BELT). We find that the BELT scheduler compares favorably with EDCA in this context.}, keywords={Online Gaming,LAN,QOS,IEEE 802.16}, pdf={supporting first.pdf}, } </bibtex> <bibtex> @inproceedings{327, author={Carrig,B.;Denieffe,D.;Murphy,J.;OSE,D.}, title={Congestion-only Charging: A Novel PricinG Mechanism for use in Diffrentiated Service Networks}, booktitle={ACM 4th International Conference on Heterogenous Networking for Quality,Reliablity,Security & Robustness,Qshine2007}, year={2007}, abstract={In networks based on the Di®erentiated Services (Di®Serv) architecture, users may be presented the opportunity to choose their Assured Forwarding (AF) class. Users will attempt to maximize their Consumer Surplus (CS) in such an environment. They can increase their CS by choosing the lowest cost AF class that satis¯es their Quality of Service (QoS) requirements. Previously the authors have proposed an algorithm known as Consumer Surplus Maximization (CSM) [2]. Although this algorithm improves CS for users, widespread adoption of the algorithm can provoke network instability. If many users switch classes at once, degradation on one AF class can easily propagate. The likelihood of such an occurrence can be reduced by replacing ¯xed per- byte or per-packet charges associated with individual AF classes with a lightweight Congestion-only Charging (CoC) pricing mechanism. An additional charge is only applied to packets that receive discernible bene¯t from belonging to a particular class. We present simulation results from a networking scenario where users connect across a single Di®Serv domain to engage in a multiplayer First Person Shooter (FPS) game.}, keywords={Pricing, Quality of Service, DiffServ}, pdf={congestion novel.pdf}, } </bibtex> <bibtex> @inproceedings{328, author={Qiao,Y.;Fallon,E.;Murphy,L.;Murphy,J.;Hanley,A.;Zhu,X.;Matthews,A.;Conway,E.}, title={SCTP Performance Issue on Path Delay Diffrential }, booktitle={WWIC 5th International Conference on Wired/Wireless Internet Communications}, year={2007}, abstract={This paper studies the effect of path delay on SCTP performance. It focuses on the SCTP fast retransmit algorithm and demonstrates that the performance in the current retransmission strategy will degrade acutely when the secondary path delay is less than the primary path delay at a certain level. The performance degradation is due to the disordered SACKs and constant congestion window size during the fast retransmit phase. Some modifications aimed at these problems are proposed and evaluated. This paper also identifies that the cause of the performance degradation in SCTP is a result of the single path configuration oriented design of the current fast retransmit algorithm. Several fast retransmission strategies are evaluated for different path delay and bandwidth configurations.}, keywords={SCTP, Multi-homing, Retransmission strategy, Path difference.}, pdf={sctp.pdf}, } </bibtex> <bibtex> @inproceedings{329, author={Hnetynka,P.;Murphy,J.}, title={Deployment of Java Based Components in Embedded Environment}, booktitle={International Conference Applied Computing}, year={2007}, abstract={Component-based development has brought the benefits of easier reuse, integration and rapid development into the software engineering process. Many contemporary component-based platforms (e.g. EJB, CCM, SOFA, Fractal) are implemented in Java because of Java features such as platform independence, dynamic loading, type safety, and others. Another reason is that Java becomes more and more ubiquitous as devices like mobile phones, PDAs, etc. embed the Java implementation. However in the area of embedded systems, applications are usually still monolithic and therefore hard to maintain and reuse. On the other hand, the embedded Java platform has several important limitations, which prevent straightforward reuse of component-based platforms. In this paper, we present how to overcome these limitations and use contemporary component platforms for developing applications for embedded systems. We demonstrate the approach on the SOFA 2.0 component platform. The paper shows that the only parts of the SOFA 2.0 platform, which have to be adapted, are the deployment process and the runtime environment. The rest of the platform suits for development for embedded systems without any change and allows for benefiting from SOFA 2.0 features like behavior validation, multiple communication styles, separated control part of components, etc.}, keywords={Hierarchical components, deployment, embedded environment, Java.}, pdf={deployment.pdf}, } </bibtex> <bibtex> @inproceedings{330, author={Carrig,B.;Denieffe,D.;Murphy,J.}, title={A User Controlled Priority Selection Strategy for Multiplayer Games}, booktitle={IEEE 4th Consumer Communications & Networking Conference}, year={2007}, abstract={Future Quality of Service (QoS) aware networks, such as those based on the Differentiated Services (DiffServ) architecture, will provide users with the opportunity to assign a priority to the traffic they receive and generate. Different priorities will entail different per-byte or per-packet charges. To aid users operating within such an environment, a priority selection strategy is required. In this paper, we propose a priority selection strategy based on the concept of Consumer Surplus (CS), which is the positive difference between utility or the user’s willingness-to-pay and cost. We then evaluate this strategy in a networking scenario where a user is involved in a multiplayer Counterstrike game, in which different priorities may be assigned to the downstream traffic. A utility curve, applicable to a First Person Shooter (FPS) game like Counterstrike, is presented. Using simulation results we show that for varied traffic loads, the CS strategy offers comparable application performance to that of always selecting the highest priority, but at a reduced cost to the user.}, keywords={Qos,DiffServ,Online Gaming}, pdf={user-controlled.pdf}, } </bibtex> <bibtex> @inproceedings{398, author={J.Bergin;L.Murphy}, title={Reducing Runtime Complexity of Long Running Application Services via Dynamic Profiling & Dynamic Bytecode Adaption for Improved Quality of Service}, booktitle={Workshop on Automating Service Quality}, year={2007}, abstract={We present a transparent optimisation framework for au- tomatically improving run-time performance of component- based enterprise applications. Run-time performance is im- proved by automatically identifying and dynamically switch- ing to an optimised but functionally equivalent program flow, for a specific transaction type. More precisely, one or more application components can have both static and dynamic inputs, where the former and its output remain mostly fixed from invocation-to-invocation, while the latter is unconstrained. Through dynamic profiling and run-time adaptation, an optimised program flow is derived, that al- lows only future execution of program points that operate on dynamic inputs and not static inputs. During execution, a target application is instrumented to switch to an opti- mised program flow. Additional instrumentation occurs to profile key program points that may invalidate an optimised program flow. If these points execute, then the application reverts back to its pre-optimised program flow. We evalu- ate and demonstrate how run-time performance for a typical thre-tired enterprise system can be improved for frequently accessed data that remains mostly static. For the applica- tion studied we showed a 49% marked improvement in the number of users serviced per second.}, keywords={adaptation, Optimisation, Caching, Profiling, Object Caching, Java Language}, pdf={reducing.pdf}, } </bibtex> <bibtex> @article{399, author={T.Taleb;A.Nafaa;L.Murphy;K.Hashimoto;N.Kato;Y.Nemoto}, title={Towards Efficient Service-Level QoS Provisioning in Large Scale 802.11-Based Networks}, journal={IEEE Network:Special Issue on Advances in Broadband Access Networks}, year={2007}, pages={42-48}, volume={21}, abstract={Along with recent advances in mobile networking and portable computing technologies, there is a trend in the telecommunications industry toward the development of efficient ubiquitous systems that can provide a set of bandwidth-intensive and real-time services to multiple users while supporting their full mobility. Largescale deployment of 802.11-based technologies will play an integral part in the construction of such ubiquitous wireless mobile systems. A challenging task in the development of such networks is efficient provisioning of QoS-enabled services for mobile users. In this context, we propose a scheme that constantly monitors the overall network performance to perform admission control and traffic conditioning at the 802.11-based access points and mobile terminals. The focus is on servicelevel fairness, where different flows from the same traffic class can still receive the same QoS level even if they have different bit rates. Furthermore, given the mobility of users, the success of any resource allocation and admission control model depends on the continuity of QoS guarantees across different WLANs. This article proposes a dynamic service level agreement negotiation protocol that allows mobile terminals to perform handoffs between different WLANs while maintaining the agreed level of service. End users also can change their service levels in response to changes in network conditions.}, keywords={Internet,802.11,Wireless Mobile,QoS}, pdf={toward efficient.pdf}, } </bibtex> <bibtex> @inproceedings{400, author={E.Fallon;J.Murphy;L.Murphy;Y.Qiao;X.Xie;A.Hanley}, title={Towards a Media Independent Handover Based Approach to Heterogenous Network Mobility }, booktitle={Irish Signals & Systems Conference 2007}, year={2007}, abstract={In recent years the number and diversity of networks available to mobile computing devices has increased dramatically. It is now feasible for a device to support multiple networks such as 3G, 802.3, 802.11 and even 802.16. Given the diversity of these networks in terms of range and bandwidth, there is a need to define a seamless approach to network handover. While current 802 standards provide the facility to detect and select access points, these mechanisms are specific to individual network types. Moreover, current 802 standards do not provide the facility, or even the availability, of information triggers for handover. In order to address issues relating to heterogeneous network handover, the IEEE have proposed a new standard: 802.21, also referred to as Media Independent Handover. It is proposed that the emerging 802.21 standard will enable a mobile device to detect and initiate handover from one network to another. Currently the 802.21 standard is at draft stage and no implementations are available. This paper investigates how elements of the proposed standard can be utilised in conjunction with the transport layer Stream Control transmission Protocol (SCTP) in order to facilitate seamless network handover. We compare a pre-emptive 802.21 oriented switch strategy against standard fault reactive SCTP strategies. Results indicate that the 802.21 oriented strategy behaves more effectively than conservative SCTP switchover strategies, and has equivalent performance to aggressive SCTP switchover strategies.}, keywords={Media Independent Handover, 802.21, SCTP, WLAN}, pdf={towards a media.pdf}, } </bibtex> <bibtex> @inproceedings{401, author={O.Ashagi;S.Murphy;L.Murphy}, title={Centralised Approaches to Subcarrier Allocation for OFDM-based 802.16 Systems Operating in License Exempt Mode}, booktitle={2nd International Conference on Cognitive Radio Oriented Wireless Networks & Communications}, year={2007}, abstract={In this paper, three approaches to allocating resources between interfering IEEE 802.16 systems operating in license exempt mode are described. The schemes differ in terms of how they implement the fairness/utilisation trade-off. The three schemes are Throughput Maximisation (ThM), Maximum Fairness (MaF), and a Neighbour Based Resource Allocation (NBRA) approach which produces an approximately fair allocation, but makes more efficient use of any unallocated resources. The three schemes are compared in terms of their overall throughput and the fairness they can deliver. They are also compared with results obtained by a distributed algorithm we proposed in previous work. It is shown that the NBRA approach gives the best throughput/fairness trade-off. Also, the results show that the distributed approach significantly underperforms the full-knowledge resource allocation schemes described here.}, keywords={IEEE 802.16,Throughput Maximisation(ThM),Maximum Fairness(MaF)}, pdf={centralised.pdf}, } </bibtex> <bibtex> @inproceedings{402, author={O.Ashagi;S.Murphy;L.Murphy}, title={A Distributed Approach to Interference Mitigation between OFDM-based 802.16 SystemsOperating in License-Exempt Mode}, booktitle={IEEE International Conference on Communications(ICC 2007) Wireless Communications Symposium }, year={2007}, abstract={An approach to mitigating interference between 802.16 license-exempt systems is proposed in this paper. More specifically, the approach focuses on solving problems which arise when two or more 802.16 systems operate on the same channel in close proximity to each other. The essence of the approach is a distributed mechanism which can apportion the available OFDM subcarriers between the different 802.16 systems. Simulation results show that the topology and the distributions of Base Stations (BSs) and the Subscriber Stations (SSs) have a significant impact on the system performance. Also, the system is very sensitive to the order in which the different nodes in the system are activated. Furthermore, the system with the given parameters can operate satisfactorily for up to 6 BSs in the same area, but scalability problems arise if more BSs are added.}, keywords={802.16 Systems,OFDM}, pdf={a distributed.pdf}, } </bibtex> <bibtex> @article{403, author={G.Muntean;P.Perry;L.Murphy}, title={A Comparison Based Study of Quality Oriented Video on Demand}, journal={IEEE Transactions on Broadcasting}, year={2007}, pages={92-102}, volume={53}, abstract={The Quality Oriented Adaptation Scheme (QOAS) is used for high bit-rate multimedia streaming in local broadband multi-service all-IP networks. It balances two opposing goals: providing high quality multimedia-based services to end-users, and increasing the infrastructure utilisation and number of customers simultaneously served. Extensive objective testing results presented in this paper show that QOAS achieves high performance in terms of end-user perceived quality, loss rate, throughput, link utilisation, and number of customers simultaneously served. These results were obtained even in highly loaded and variable delivery conditions caused by traffic of different types, sizes, and variation patterns. QOAS performance was assessed stand-alone and in comparison with other existing solutions, adaptive and non-adaptive.}, keywords={Adaptive video streaming, feedback control, grading scheme, end-user perceived quality.}, pdf={a comparison.pdf}, } </bibtex> <bibtex> @article{409, author={C.H.Muntean;G.M.Muntean;J.McManis;A.I.Cristea}, title={Quality of Experience-LAOS:Create Once,Use Many,Use Anywhere}, journal={International Journal of Learning Technology}, year={2007}, pages={209-229}, volume={3}, abstract={This paper proposes QoE-LAOS, a Quality of Experience-oriented adaptive authoring model that enables performance-aware adaptation. It extends the existing LAOS authoring model in order to consider display and delivery performance issues. QoE-LAOS involves the addition of three new QoE sublayers: QoE Content Features sublayer, QoE Characteristics sublayer and QoE Rules sublayer. These proposed QoE sublayers are deployed at LAOS's Domain, Adaptation and Presentation Models, respectively. This paper formalises and exemplifies QoE-LAOS and discusses authoring-related issues in relation to each new sublayer. }, keywords={adaptive hypermedia, adaptive educational hypermedia, AEH, adaptive author assistance, semi-automatic adding, authoring models, authoring tools, adaptive web application engineering, adaptive web application authoring, adaptive learning, adaptive systems,}, pdf={quality of experience.pdf}, } </bibtex> <bibtex> @inproceedings{435, author={Z.Fratczak;Gabriel-Miro Muntean;K.Collins}, title={Electronic Monitoring of Nutritional Components}, booktitle={Information & Telecommunication Technology}, year={2007}, abstract={Obesity and other diseases related to unhealthy diet are problems of near epidemic proportion and become a growing issue every year. This paper presents a solution to this issue by proposing the use of a computer application that is able to suggest the appropriate products related to one’s diet, and to keep track of nutritional intake. The paper also describes the principle of the solution, system architecture and implementation and presents testing results. If the application’s instructions are followed by users it is expected that an optimal diet will be achieved resulting in users good health.}, keywords={Healthy diet, e-health, utility function, nutrition control}, pdf={electronic.pdf}, } </bibtex> <bibtex> @inproceedings{440, author={J.Adams;Gabriel-Miro Muntean}, title={Power Save Adaptation Algorithm for Multimedia Streaming to Mobile Devices}, booktitle={IEEE International Conference on Portable Information Devices}, year={2007}, abstract={Batteries have not followed the exponential technological improvements of other mobile device related hardware, such as CPU, memory and wireless networking. Battery power often introduces significant limitations to the use of mobile devices and their applications, including those involved in multimedia streaming that have significant high power requirements. This paper proposes a power save adaptation algorithm for mobile multimedia streaming that aims to increase streaming time given limited battery power resources. The multimedia streaming process is divided into three stages: data reception, decoding and playing and power saving solutions for each of these stages are proposed. These power save mechanisms are then combined to give the power save algorithm. Preliminary tests results show that significant increases in battery lifetime have been achieved when the power save mechanisms proposed in this paper are used.}, keywords={Algorithm,Multimedia Streaming,Mobile Devices}, pdf={power save.pdf}, } </bibtex> <bibtex> @inproceedings{441, author={E.Casey;Gabriel-Miro Muntean}, title={A Mechanism for Greediness Management whenStreaming Multimedia to Portable Devices}, booktitle={IEEE International Conference on Portable Information Devices}, year={2007}, abstract={The majority of streaming solutions use rate adaptaion based on congestion avoidance mechanisms that try to obtain as much bandwidth as possible from the limited network resources. This is good if we assume that all clients have equal requirements. However this is rarely the case as devices have unique characterstics ( e.g. screen size, screen resolution, location etc) that influence streaming related parameters & consequently the experience obtained by the end user.Due to the inherent greediness of streaming protocols & lack of knowledge about the characterstics of the users devices, this may result in certain devices receiving higher bandwidth share than they actually need & others not receiving enough,affecting the users perceived quality. Therefore there is a need to allow for client diffrentiation in order to provide an acceptable service for all cliemts,taking their device characterstics into account.This paper proposes a Greediness Control Algorithm(GCA),a specially designed application layer solution that tunes the greediness of the multimedia streaming based on client priority, to make more efficient use of the wireless network and increase the overall user perceived quality.}, keywords={Algorithm,Multimedia,Portable Devices}, pdf={mechanism.pdf}, } </bibtex> <bibtex> @inproceedings{442, author={Gabriel-Miro Muntean;N.Cranley}, title={User Quality of Experience-Aware Multimedia Streaming over Wireless Home Area Network}, booktitle={IEEE Vehicular Technology Conference}, year={2007}, abstract={For multimedia streaming over wireless networks, there is a trade-off between the capacity of the wireless links and the end-user perceived-quality, which can be affected by the compression scheme used, content characteristics and adaptation algorithm (if any). In this paper, this trade-off is investigated for streaming various motion content multimedia over an IEEE 802.11b-based Wireless-Home Area Network using the Quality-Oriented Adaptation Scheme (QOAS). QOAS performance is compared to that of a non-adaptive scheme when using MPEG-2 and MPEG-4 encoding in terms of average end-user perceived quality, number of streaming sessions concurrently supported, loss rate, delay, jitter and total throughput. Simulation results show that by using QOAS and MPEG-4 encoded streams a much higher number of concurrent streams are supported at an average quality above “good” level on the ITU-T five-point quality scale in comparison with other situations. In this case all the other streaming performance parameters were also significantly better.}, keywords={Adaptive video streaming, Wireless Home Area Network, grading scheme, end-user perceived quality.}, pdf={user quality.pdf}, } </bibtex> <bibtex> @inproceedings{443, author={J.Adams;Gabriel-Miro Muntean}, title={Adaptive Buffer Power Save Mechanism for Mobile Multimedia Streaming}, booktitle={IEEE International Conference on Communication}, year={2007}, abstract={Wireless networks are becoming a part of everyday life for many people. When a mobile device has wireless LAN capability, multimedia content can be streamed over a wireless network to that device. However, a major disadvantage of all mobile devices is their limited battery lifetime. Multimedia streaming puts extra pressure on the battery, causing it to discharge faster. In some cases, streaming tasks cannot be completed purely because the battery of the device becomes fully discharged, which causes significant user dissatisfaction. Consequently, it is necessary to devise mechanisms to enable longer battery lifetime in order to support complex applications such as those involving mobile multimedia streaming. This paper proposes an Adaptive-Buffer Power Save mechanism (AB-PSM) for increasing the battery life of mobile devices during multimedia streaming. This increase is achieved by controlling how and when data is sent over a wireless LAN. AB-PSM introduces an additional buffer which hides data from the station it is intended for, allowing it to return to sleep and consequently saving power. Data is eventually delivered in one of the station’s following attempts to receive it. Tests involving AB-PSM have been performed and show good results in terms of significant increases in battery lifetime. The comparison between AB-PSM and the IEEE 802.11 legacy power save mechanism shows important increases in battery lifetime of more than 100%.}, keywords={Wireless Network,Mobile Communications}, pdf={adaptive buffer.pdf}, } </bibtex> <bibtex> @inproceedings{444, author={T.Casey;Gabriel-Miro Muntean;D.Denieffe}, title={Influence of Mobile User Velocity on Data Transfer in a Muti-Network Wireless Environments}, booktitle={9th International Conference on Mobile & Wireless Communication Networks}, year={2007}, abstract={Heterogeneous wireless environments are now a reality in many urban areas. Designing and deploying a wireless network in such an environment is complicated by the unpredictable propagation paths of radio signals and by the unpredictable behaviour of the network users themselves. Network simulation and modelling can be used to assist in the design process. However, in order for simulation models to be effective they must be realistic. Efforts have been made to render simulation models more realistic through the analysis of real world wireless networks and through the examination and evaluation of existing simulation models. The most fundamental characteristics of a mobile user are their mobility, and the speed at which they move. The various velocities used in simulation models are unrealistic with respect to pedestrian behaviour in urban environments. In addition, the possible influence of mobile user velocity on the amount of data transferred by the user is not considered. In this paper we examine the influence of a mobile user’s velocity on throughput in a wireless network using a range of realistic velocities.}, keywords={heterogeneous wireless network environment,}, pdf={influence.pdf}, } </bibtex> <bibtex> @inproceedings{445, author={Gabriel-Miro Muntean}, title={Effect of Delivery Latency,Feedback Frequency & Network Load on Adaptive Multimedia Streaming}, booktitle={IEEE 32nd Local Computer Neworks Conference }, year={2007}, abstract={As video on demand systems gain popularity, it seems likely that the desire to serve a high number of customers from limited network resources could lead to a degradation of the endusers’ perceived quality. Quality-Oriented Adaptation Scheme (QOAS) balances the need for high quality with increased network utilization when streaming multimedia. QOAS requires client-side monitoring of some transmission-related parameters, grading of the end-user’s quality and feedback that informs the server about the received quality. In response to this feedback, the server adjusts the streaming process in order to maximize the end-user perceived quality in the current conditions. This paper studies the effect of delivery latency and feedback frequency on quality-oriented adaptive multimedia streaming. It also shows how high end-user perceived quality is maintained in the presence of different types of background traffic while recording a significant increase in link utilization and a very low loss rate.}, keywords={Adaptive video streaming, grading scheme, end-user}, pdf={effect of delivery.pdf}, } </bibtex> <bibtex> @inproceedings{452, author={Gabriel-Miro Muntean;N.Cranley}, title={Resource Efficient Quality-Oriented Wireless Broadcasting of Adaptive Multimedia Content}, booktitle={IEEE Trans. on Broadcasting}, year={2007}, abstract={The performance of multimedia stream delivery is influenced by encoding scheme, streaming solution and network conditions. This paper studies the performance of multimedia streaming when using the Quality-Oriented Adaptive Scheme (QOAS) over an IEEE 802.11b Wireless LAN and compares it to that achieved when using other solutions that do not consider end-user quality in their delivery process such as TFRC, LDA+, and non-adaptive schemes. The performance is assessed in terms of average end-user perceived quality, number of concurrent streaming sessions, loss rate, delay, jitter and total throughput when streaming MPEG-4 encoded content. Simulation results show that the QOAS out-performs these other streaming solutions in all aspects of network delivery. QOAS can support a greater number of concurrent streaming sessions at a higher average quality. In addition, for the same number of clients QOAS achieved a higher average end-user quality, as well as better network delivery streaming performance parameters.}, keywords={Adaptive multimedia streaming, end-user quality}, pdf={rsource.pdf}, } </bibtex> <bibtex> @inbook{457, author={O.Ormond;Gabriel-Miro Muntean}, title={Dynamic Handover in Wireless LAN/MAN Heterogenous Networks}, publisher={Mobile WiMAX:Towards Broadband Wireless Metropolitan Area Networks}, year={2007}, abstract={In future generations of wireless networks, it is expected that different users with various multi-homed personal wireless devices will have the option of accessing their desired services via different available radio access networks. Given the variability of the radio environment properties and user mobility, the availability and characteristics of an access network will change in time and are highly dependent on location. As a result, dynamic reselection of the access network will be a necessary part of the mobility management mechanism (which maintains the session connectivity as the user moves and/or the available access characteristics change). In their selection of a radio access network customers will consider cost and perceptive quality preferences for the current application and will rely on intelligent network selection decision strategies to aid or automate their choice.}, keywords={Wireless Network,Radio Network}, pdf={dynamic.pdf}, } </bibtex> <bibtex> @inbook{458, author={C.H.Muntean;Gabriel-Miro Muntean}, title={End User Quality of Experience Aware Personalised in E-Learning}, publisher={Architecture Solutions for E-Learning Systems}, year={2007}, abstract={In the context of new devices and with a variety of network technologies that allow access to the Internet, the providers of e-learning materials have to ensure that the users have a positive experience using their e-learning systems and they are happy to re-use them. Adaptive Hypermedia research aims to provide personalised educational material that ensures a positive learning experience for the end-users. However, user experience is dependent not only on the content served to them, but also on the user perceived performance of the e-learning system. This leads to a new dimension of individual differences between Web users: the end-user Quality of Experience (QoE). We have proposed a solution for Adaptive Hypermedia Systems (AHS) that provides satisfactory end-user QoE through the use of a new QoE layer. This layer attempts to take into account multiple factors affecting QoE in relation to the delivery of a wide range of Web components such as text, images, video, audio. The effectiveness of our QoE layer has been tested in comparison to a standard educational AHS and the results of these tests are presented in this paper. Different educational-based evaluation techniques such as learner achievement analysis, learning performance assessment, usability survey and correlation analysis between individual student performance and judgment on system usability were applied in order to fully assess the performance of the proposed QoE layer. Results of the tests showed that the use of the QoE layer brought significant improvements in terms of user learning performance, system usability and user satisfaction with the personalised e-learning system while not affecting the user learning achievement }, keywords={end-user QoE, adaptive hypermedia, e-learning, end-user perceived performance, learning performance }, pdf={end-user.doc}, } </bibtex>