Ramona Trestian | Middlesex University (original) (raw)
Papers by Ramona Trestian
Telematics and Informatics, 2017
Nowadays people tend to spend most of their time in front of a screen, and expect to be able to c... more Nowadays people tend to spend most of their time in front of a screen, and expect to be able to connect to the Internet anytime and anywhere and from any type of mobile device. Therefore, fast surfing speed on Internet, high resolution display screen, advanced multi-core processor and lasting battery support are becoming the significant standards in the nowadays mobile devices. In this context the network operators must be able to differentiate between their multiscreen offerings in order to ensure uninterrupted, continuous, and smooth video streaming with minimal delay, jitter, and packet loss. This paper proposes a novel Device-Oriented Energy-Aware Utility-based Priority scheduling (DE-UPS) algorithm which makes use of device differentiation in order to ensure seamless multimedia services over LTE networks. The priority decision is based on the device classification, energy consumption of the mobile device and the multimedia stream tolerance to packet loss ratio.
NOMS 2016 - 2016 IEEE/IFIP Network Operations and Management Symposium, 2016
2015 8th IFIP Wireless and Mobile Networking Conference (WMNC), 2015
39Th Annual Ieee Conference on Local Computer Networks, Sep 9, 2014
One of the main challenges towards reliable multicast transmissions over wireless networks is the... more One of the main challenges towards reliable multicast transmissions over wireless networks is the dynamics of the wireless links (e.g. wireless errors, fading, interference, collisions, etc.) that can cause retransmissions overhead over the limited available bandwidth. To this end this paper considers the scenario of wireless multicast networks where network coding is applied to improve network throughput. We first propose a novel cross-layer optimisation framework for network topology design in order to optimise the wireless multicast rate, data flow of the wireless links, energy supply and node lifetime. The performance of the proposed solution is evaluated and compared against other solutions from the literature in terms of system throughput, total energy, and network lifetime. The results show that the proposed cross-layer design outperforms the other schemes involved, reaching up to 50% increase in the system throughput.
IEEE Transactions on Wireless Communications, 2015
2015 IEEE International Symposium on Broadband Multimedia Systems and Broadcasting, 2015
The small cell deployment is seen as a promising solution for the network operators to help them ... more The small cell deployment is seen as a promising solution for the network operators to help them cope with the increasing number of mobile broadband data subscribers and their bandwidth-intensive application demands. The result is a HetNet, heterogeneous network environment with a combination of macro-cells and small cells to spread the traffic load, increase the bitrates and maintain the service quality. In this context, network selection mechanisms will be required to keep the mobile users always best experienced. In this paper, we propose a theoretical framework URAN, for combining utility-based network selection mechanism with reputation-based systems. URAN makes use of the user preferences and service requirements to define a network reputation factor which reflects the user satisfaction on the network's previous service guarantee to the mobile user.
Handbook of Research on Innovations in Information Retrieval, Analysis, and Management, 2016
2015 IEEE Conference on Computer Communications Workshops (INFOCOM WKSHPS), 2015
2015 IEEE International Conference on Communications (ICC), 2015
The rapid advances in technology lead to a massmarket adoption of the multi-radio high-end smartp... more The rapid advances in technology lead to a massmarket adoption of the multi-radio high-end smartphone devices and an exponential increase in the mobile broadband data traffic. In the search for a solution to cope with this explosion of data traffic, Device-to-Device (D2D) communications become an attractive approach for enhancing the performance of cellular networks. The emerging of WiFi Direct framework introduced new opportunities for mobile-to-mobile opportunistic offloading. In this context, this paper proposes ECO-M, an Energy-efficient Cluster-Oriented solution for Multimedia delivery in a LTE D2D environment using WiFi Direct. Experimental test-bed measurements and numerical results show the efficiency of such a solution in terms of energy efficiency, battery discharge and battery lifetime when compared with a standard LTE environment. Subjective tests were carried out to study not only the impact of user perceived quality on the various multimedia quality levels choices but also the impact of user preferences in terms of energy conservation versus multimedia quality.
2015 IEEE International Symposium on Broadband Multimedia Systems and Broadcasting, 2015
One of the dominant traffic types in today's mobile and wireless communication environment is the... more One of the dominant traffic types in today's mobile and wireless communication environment is the video content. The exponential increase in video traffic is due to the popularity of video-sharing websites (e.g., YouTube, Facebook) and the increasing affordability of high-end mobile devices. However, as video is known to be one of the most power hungry applications, the energy conservation has become significant concern. To this end, this paper analyses the impact of the video content on the energy consumption of a high-end mobile device. Moreover, subjective tests are carried out in order to study the impact of the video content on the user perceived Quality of Experience. An investigation on the impact of user preferences on the video quality assessment is also conducted. The results of this study could lay a foundation for future investigation in building an energy-efficient adaptive multimedia mechanism that takes into consideration the video content type and user preferences.
This paper investigates multiple access techniques for wireless downlink in cloud radio access ne... more This paper investigates multiple access techniques for wireless downlink in cloud radio access networks (CRANs) where all base stations (BSs) are connected via a cloud. We first propose a power allocation scheme that makes use of nonorthogonal multiple access to allocate the power at the BSs based on their relative wireless distances to the cloud. Specifically, a successive interference cancellation mechanism is designed at the cloud to lay multiple BSs over each other in the power domain. We then analyse the achievable throughput of the NOMA in the CRANs. The derived expressions not only show the effectiveness of the proposed NOMA over the conventional orthogonal frequency division multiple access (OFDMA) but also allow us to develop an algorithm to find the optimal number of BSs in the CRANs. Finally, numerical results are provided to show an improvement of up to eight times of the sum data rate and a higher number of BSs that could be maintained with the proposed NOMA over the OFDMA scheme as well as evaluating the impact of the wireless propagation environment and channel quality on the system throughput and cloud-edge throughput performance.
Computer Networks, 2015
ABSTRACT This paper considers wireless multicast networks where network coding (NC) is applied to... more ABSTRACT This paper considers wireless multicast networks where network coding (NC) is applied to improve network throughput. A novel joint topology and cross-layer design is proposed to miximise the network throughput subject to various quality-of-service constraints, such as: wireless multicast rate, wireless link capacity, energy supply and network lifetime. Specifically, a heuristic NC-based link-controlled routing tree algorithm is developed to reduce the number of required intermediate nodes. The proposed algorithm facilitates the optimisation of the wireless multicast rate, data flow of wireless links, energy supply and lifetime of nodes through a novel cross-layer design. The proposed joint topology and cross-layer design is evaluated and compared against other schemes from the literature. The results show that the proposed scheme can achieve up to 50% increase in the system throughput when compared to a classic approach.
Proceedings of the 2015 1st IEEE Conference on Network Softwarization (NetSoft), 2015
ABSTRACT Over the past decade there has been an exponential increase in the Internet traffic espe... more ABSTRACT Over the past decade there has been an exponential increase in the Internet traffic especially with the proliferation of cloud computing and other distributed data services. This explosion of data traffic with its dynamically changing traffic patterns and flows might result in degradation of the application performance. In this context, there is a need for an intelligent and efficient network management system that delivers guaranteed services. To this extent, this paper proposes BaProbSDN, a probabilistic end-to-end Quality of Service (QoS) routing mechanism for Software Defined Networks (SDN). The QoS routing algorithm employs the bandwidth availability metric as a QoS routing constraint for unicast data delivery. BaProbSDN makes use of Bayes' theorem and Bayesian network model to determine the link probability in order to select the route that satisfies the given bandwidth constraint. The performance of the proposed probabilistic QoS routing algorithm was tested in a simulation-based environment and compared against the widest-shortest path routing (WSR) algorithm.
Proceeding of IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks 2014, 2014
The reduction of energy consumption is a major concern in the current telecommunications environm... more The reduction of energy consumption is a major concern in the current telecommunications environment -especially with the growth in usage of energy-hungry multimediacentric applications on high-end mobile devices. In this context, this paper proposes eSMART, an Energy-efficient Scalable Multimedia Broadcast Transmission mechanism, that considers the energy-quality trade-off to reduce battery power consumption (increase energy saving) of heterogeneous mobile devices while maintaining acceptable perceived quality levels of received video. A real experimental test-bed has been built to analyze the impact of different multimedia scalability factors on the energy consumption of various mobile devices receiving broadcast content. Overall mobile device energy-saving is modeled using the accumulative effect of adaptive scalable video playback energy saving and time-sliced broadcast reception based radio-receiver's energy saving. eSMART's optimization framework performs user-centric adaptive encoding of scalable video that is broadcast to heterogeneous user equipments. eSMART serves more users at improved quality of experience levels and achieves up to 69% increase in mobile device energy savings as compared to a nonadaptive time-slicing scheme from the literature.
Wireless Networks, 2014
As mobile devices have become more affordable, easy to use and powerful, the number of mobile use... more As mobile devices have become more affordable, easy to use and powerful, the number of mobile users and their bandwidth demands have experienced a significant growth. Considering the rising popularity of power hungry applications (e.g. multimedia), battery power capacity is an important concern -as upgrades are not keeping up with the advances in other technologies (e.g., Central Processing Unit (CPU) and memory). Mobile users now demand better power and battery management techniques to prolong their mobile battery performance. This, together with the need for green Information Communications Technology (ICT), provides motivation for researchers to develop energy efficient techniques to reduce the power consumption in next-generation wireless networks while meeting user's quality expectations. This paper conducts a realistic performance evaluation of a number of widely used Multi Attribute Decision Making (MADM)-based methods for network selection that aim at keeping the mobile users Always Best Connected anywhere and anytime. The main trade-off parameters considered include energy efficiency and user perceived quality levels for multimedia streaming. The energy consumption is modeled using real experimental results for an Android Mobile device. Similarly, the multimedia quality function was modeled using real user data, combined with a qualitative study to determine the resulting mean opinion scores. The performance analysis shows that the Weighted Multiplicative Method (MEW) finds a better energy-quality trade-off for users in a heterogeneous wireless environment in comparison with three other MADM solutions.
This paper investigates multiple access techniques for downlink in cloud radio access networks (C... more This paper investigates multiple access techniques for downlink in cloud radio access networks (CRANs), which have recently been proposed to connect all base stations (BSs) via a cloud. We first propose a non-orthogonal multiple access (NOMA) scheme to allocate the power at the BSs based on their relative distances to the cloud. Specifically, a successive interference cancellation mechanism is designed at the cloud to lay multiple BSs over each other in the power domain. We then analyse the achievable throughput of the NOMA in the CRANs. The derived expressions not only show the effectiveness of the proposed NOMA over the conventional orthogonal frequency division multiple access (OFDMA) but also evaluate the impact of the BSs positioning and propagation environment on the throughput performance. Finally, numerical results are provided to show an improvement of up to eight times of the sum data rate that could be achieved with the proposed NOMA over the OFDMA scheme.
IEEE Transactions on Broadcasting, 2015
This paper presents an innovative multi-faceted architecture, named eWU-TV, that provides an ener... more This paper presents an innovative multi-faceted architecture, named eWU-TV, that provides an energy efficient, user-centric, adaptive digital television (DTV) broadcast over Wi-Fi. To cater to the varied properties of the user equipments (UEs), the proposed framework broadcasts DTV content in the form of scalable video coded content that is adapted to suit the subscribers' requirements. The user-centricity is in terms of UE device display size, user preferences for video quality profile based on device energy saving, and UE transmission technology support (DVB-T/H or Wi-Fi). Mathematical models on device battery discharge, QoE, and user preference are devised that closely approximate the results of device battery discharge experiments on DTV reception by heterogeneous devices over Wi-Fi/DVB-T, subjective video quality assessment study, and statistical survey of user preference. The proposed eWU-TV performance optimization framework is based on the developed models. The framework ensures that the adaptive scalable broadcast reception via Wi-Fi serves more number of users with higher quality of user experience and with provisions for significant device energy saving.
IEEE Transactions on Mobile Computing, 2000
This paper presents a novel cross-layer optimization framework to improve the quality of user exp... more This paper presents a novel cross-layer optimization framework to improve the quality of user experience (QoE) and energy efficiency of the heterogeneous wireless multimedia broadcast receivers. This joint optimization is achieved by grouping the users based on their device capabilities and estimated channel conditions experienced by them and broadcasting adaptive content to these groups. The adaptive multimedia content is obtained by using scalable video coding (SVC) with optimal source encoding parameters resulted from an innovative cooperative game. Energy saving at user terminals results from using a layer-aware time slicing approach in the transmission stage. A trade-off between energy saving and QoE is observed, and is incorporated in the definition of a utility function of the players in the formulated heterogeneous user composition and physical channel aware game. An adaptive modulation and coding scheme is also optimally incorporated in order to maximize the reception quality of the broadcast receivers, while maximizing the network broadcast capacity. Compared to the conventional broadcast schemes, the proposed framework shows an appreciable improvement in QoE levels for all users, while achieving higher energy-savings for the energy constrained users.
IEEE Transactions on Broadcasting, 2000
The continuing growth in video content exchanged by mobile users creates challenges for the netwo... more The continuing growth in video content exchanged by mobile users creates challenges for the network service providers in terms of supporting seamless multimedia delivery at high quality levels, especially given the existing wireless network resources. A solution which deals with this mobile broadband data growth is to make use of multiple networks supported by diverse radio access technologies. This multi-access solution requires innovative network selection mechanisms to keep the mobile users "always best connected" anywhere and anytime. Additionally, there is a need to develop energy efficient techniques in order to reduce power consumption in nextgeneration wireless networks, while meeting user quality expectations. In this context, this paper proposes an Enhanced
Telematics and Informatics, 2017
Nowadays people tend to spend most of their time in front of a screen, and expect to be able to c... more Nowadays people tend to spend most of their time in front of a screen, and expect to be able to connect to the Internet anytime and anywhere and from any type of mobile device. Therefore, fast surfing speed on Internet, high resolution display screen, advanced multi-core processor and lasting battery support are becoming the significant standards in the nowadays mobile devices. In this context the network operators must be able to differentiate between their multiscreen offerings in order to ensure uninterrupted, continuous, and smooth video streaming with minimal delay, jitter, and packet loss. This paper proposes a novel Device-Oriented Energy-Aware Utility-based Priority scheduling (DE-UPS) algorithm which makes use of device differentiation in order to ensure seamless multimedia services over LTE networks. The priority decision is based on the device classification, energy consumption of the mobile device and the multimedia stream tolerance to packet loss ratio.
NOMS 2016 - 2016 IEEE/IFIP Network Operations and Management Symposium, 2016
2015 8th IFIP Wireless and Mobile Networking Conference (WMNC), 2015
39Th Annual Ieee Conference on Local Computer Networks, Sep 9, 2014
One of the main challenges towards reliable multicast transmissions over wireless networks is the... more One of the main challenges towards reliable multicast transmissions over wireless networks is the dynamics of the wireless links (e.g. wireless errors, fading, interference, collisions, etc.) that can cause retransmissions overhead over the limited available bandwidth. To this end this paper considers the scenario of wireless multicast networks where network coding is applied to improve network throughput. We first propose a novel cross-layer optimisation framework for network topology design in order to optimise the wireless multicast rate, data flow of the wireless links, energy supply and node lifetime. The performance of the proposed solution is evaluated and compared against other solutions from the literature in terms of system throughput, total energy, and network lifetime. The results show that the proposed cross-layer design outperforms the other schemes involved, reaching up to 50% increase in the system throughput.
IEEE Transactions on Wireless Communications, 2015
2015 IEEE International Symposium on Broadband Multimedia Systems and Broadcasting, 2015
The small cell deployment is seen as a promising solution for the network operators to help them ... more The small cell deployment is seen as a promising solution for the network operators to help them cope with the increasing number of mobile broadband data subscribers and their bandwidth-intensive application demands. The result is a HetNet, heterogeneous network environment with a combination of macro-cells and small cells to spread the traffic load, increase the bitrates and maintain the service quality. In this context, network selection mechanisms will be required to keep the mobile users always best experienced. In this paper, we propose a theoretical framework URAN, for combining utility-based network selection mechanism with reputation-based systems. URAN makes use of the user preferences and service requirements to define a network reputation factor which reflects the user satisfaction on the network's previous service guarantee to the mobile user.
Handbook of Research on Innovations in Information Retrieval, Analysis, and Management, 2016
2015 IEEE Conference on Computer Communications Workshops (INFOCOM WKSHPS), 2015
2015 IEEE International Conference on Communications (ICC), 2015
The rapid advances in technology lead to a massmarket adoption of the multi-radio high-end smartp... more The rapid advances in technology lead to a massmarket adoption of the multi-radio high-end smartphone devices and an exponential increase in the mobile broadband data traffic. In the search for a solution to cope with this explosion of data traffic, Device-to-Device (D2D) communications become an attractive approach for enhancing the performance of cellular networks. The emerging of WiFi Direct framework introduced new opportunities for mobile-to-mobile opportunistic offloading. In this context, this paper proposes ECO-M, an Energy-efficient Cluster-Oriented solution for Multimedia delivery in a LTE D2D environment using WiFi Direct. Experimental test-bed measurements and numerical results show the efficiency of such a solution in terms of energy efficiency, battery discharge and battery lifetime when compared with a standard LTE environment. Subjective tests were carried out to study not only the impact of user perceived quality on the various multimedia quality levels choices but also the impact of user preferences in terms of energy conservation versus multimedia quality.
2015 IEEE International Symposium on Broadband Multimedia Systems and Broadcasting, 2015
One of the dominant traffic types in today's mobile and wireless communication environment is the... more One of the dominant traffic types in today's mobile and wireless communication environment is the video content. The exponential increase in video traffic is due to the popularity of video-sharing websites (e.g., YouTube, Facebook) and the increasing affordability of high-end mobile devices. However, as video is known to be one of the most power hungry applications, the energy conservation has become significant concern. To this end, this paper analyses the impact of the video content on the energy consumption of a high-end mobile device. Moreover, subjective tests are carried out in order to study the impact of the video content on the user perceived Quality of Experience. An investigation on the impact of user preferences on the video quality assessment is also conducted. The results of this study could lay a foundation for future investigation in building an energy-efficient adaptive multimedia mechanism that takes into consideration the video content type and user preferences.
This paper investigates multiple access techniques for wireless downlink in cloud radio access ne... more This paper investigates multiple access techniques for wireless downlink in cloud radio access networks (CRANs) where all base stations (BSs) are connected via a cloud. We first propose a power allocation scheme that makes use of nonorthogonal multiple access to allocate the power at the BSs based on their relative wireless distances to the cloud. Specifically, a successive interference cancellation mechanism is designed at the cloud to lay multiple BSs over each other in the power domain. We then analyse the achievable throughput of the NOMA in the CRANs. The derived expressions not only show the effectiveness of the proposed NOMA over the conventional orthogonal frequency division multiple access (OFDMA) but also allow us to develop an algorithm to find the optimal number of BSs in the CRANs. Finally, numerical results are provided to show an improvement of up to eight times of the sum data rate and a higher number of BSs that could be maintained with the proposed NOMA over the OFDMA scheme as well as evaluating the impact of the wireless propagation environment and channel quality on the system throughput and cloud-edge throughput performance.
Computer Networks, 2015
ABSTRACT This paper considers wireless multicast networks where network coding (NC) is applied to... more ABSTRACT This paper considers wireless multicast networks where network coding (NC) is applied to improve network throughput. A novel joint topology and cross-layer design is proposed to miximise the network throughput subject to various quality-of-service constraints, such as: wireless multicast rate, wireless link capacity, energy supply and network lifetime. Specifically, a heuristic NC-based link-controlled routing tree algorithm is developed to reduce the number of required intermediate nodes. The proposed algorithm facilitates the optimisation of the wireless multicast rate, data flow of wireless links, energy supply and lifetime of nodes through a novel cross-layer design. The proposed joint topology and cross-layer design is evaluated and compared against other schemes from the literature. The results show that the proposed scheme can achieve up to 50% increase in the system throughput when compared to a classic approach.
Proceedings of the 2015 1st IEEE Conference on Network Softwarization (NetSoft), 2015
ABSTRACT Over the past decade there has been an exponential increase in the Internet traffic espe... more ABSTRACT Over the past decade there has been an exponential increase in the Internet traffic especially with the proliferation of cloud computing and other distributed data services. This explosion of data traffic with its dynamically changing traffic patterns and flows might result in degradation of the application performance. In this context, there is a need for an intelligent and efficient network management system that delivers guaranteed services. To this extent, this paper proposes BaProbSDN, a probabilistic end-to-end Quality of Service (QoS) routing mechanism for Software Defined Networks (SDN). The QoS routing algorithm employs the bandwidth availability metric as a QoS routing constraint for unicast data delivery. BaProbSDN makes use of Bayes' theorem and Bayesian network model to determine the link probability in order to select the route that satisfies the given bandwidth constraint. The performance of the proposed probabilistic QoS routing algorithm was tested in a simulation-based environment and compared against the widest-shortest path routing (WSR) algorithm.
Proceeding of IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks 2014, 2014
The reduction of energy consumption is a major concern in the current telecommunications environm... more The reduction of energy consumption is a major concern in the current telecommunications environment -especially with the growth in usage of energy-hungry multimediacentric applications on high-end mobile devices. In this context, this paper proposes eSMART, an Energy-efficient Scalable Multimedia Broadcast Transmission mechanism, that considers the energy-quality trade-off to reduce battery power consumption (increase energy saving) of heterogeneous mobile devices while maintaining acceptable perceived quality levels of received video. A real experimental test-bed has been built to analyze the impact of different multimedia scalability factors on the energy consumption of various mobile devices receiving broadcast content. Overall mobile device energy-saving is modeled using the accumulative effect of adaptive scalable video playback energy saving and time-sliced broadcast reception based radio-receiver's energy saving. eSMART's optimization framework performs user-centric adaptive encoding of scalable video that is broadcast to heterogeneous user equipments. eSMART serves more users at improved quality of experience levels and achieves up to 69% increase in mobile device energy savings as compared to a nonadaptive time-slicing scheme from the literature.
Wireless Networks, 2014
As mobile devices have become more affordable, easy to use and powerful, the number of mobile use... more As mobile devices have become more affordable, easy to use and powerful, the number of mobile users and their bandwidth demands have experienced a significant growth. Considering the rising popularity of power hungry applications (e.g. multimedia), battery power capacity is an important concern -as upgrades are not keeping up with the advances in other technologies (e.g., Central Processing Unit (CPU) and memory). Mobile users now demand better power and battery management techniques to prolong their mobile battery performance. This, together with the need for green Information Communications Technology (ICT), provides motivation for researchers to develop energy efficient techniques to reduce the power consumption in next-generation wireless networks while meeting user's quality expectations. This paper conducts a realistic performance evaluation of a number of widely used Multi Attribute Decision Making (MADM)-based methods for network selection that aim at keeping the mobile users Always Best Connected anywhere and anytime. The main trade-off parameters considered include energy efficiency and user perceived quality levels for multimedia streaming. The energy consumption is modeled using real experimental results for an Android Mobile device. Similarly, the multimedia quality function was modeled using real user data, combined with a qualitative study to determine the resulting mean opinion scores. The performance analysis shows that the Weighted Multiplicative Method (MEW) finds a better energy-quality trade-off for users in a heterogeneous wireless environment in comparison with three other MADM solutions.
This paper investigates multiple access techniques for downlink in cloud radio access networks (C... more This paper investigates multiple access techniques for downlink in cloud radio access networks (CRANs), which have recently been proposed to connect all base stations (BSs) via a cloud. We first propose a non-orthogonal multiple access (NOMA) scheme to allocate the power at the BSs based on their relative distances to the cloud. Specifically, a successive interference cancellation mechanism is designed at the cloud to lay multiple BSs over each other in the power domain. We then analyse the achievable throughput of the NOMA in the CRANs. The derived expressions not only show the effectiveness of the proposed NOMA over the conventional orthogonal frequency division multiple access (OFDMA) but also evaluate the impact of the BSs positioning and propagation environment on the throughput performance. Finally, numerical results are provided to show an improvement of up to eight times of the sum data rate that could be achieved with the proposed NOMA over the OFDMA scheme.
IEEE Transactions on Broadcasting, 2015
This paper presents an innovative multi-faceted architecture, named eWU-TV, that provides an ener... more This paper presents an innovative multi-faceted architecture, named eWU-TV, that provides an energy efficient, user-centric, adaptive digital television (DTV) broadcast over Wi-Fi. To cater to the varied properties of the user equipments (UEs), the proposed framework broadcasts DTV content in the form of scalable video coded content that is adapted to suit the subscribers' requirements. The user-centricity is in terms of UE device display size, user preferences for video quality profile based on device energy saving, and UE transmission technology support (DVB-T/H or Wi-Fi). Mathematical models on device battery discharge, QoE, and user preference are devised that closely approximate the results of device battery discharge experiments on DTV reception by heterogeneous devices over Wi-Fi/DVB-T, subjective video quality assessment study, and statistical survey of user preference. The proposed eWU-TV performance optimization framework is based on the developed models. The framework ensures that the adaptive scalable broadcast reception via Wi-Fi serves more number of users with higher quality of user experience and with provisions for significant device energy saving.
IEEE Transactions on Mobile Computing, 2000
This paper presents a novel cross-layer optimization framework to improve the quality of user exp... more This paper presents a novel cross-layer optimization framework to improve the quality of user experience (QoE) and energy efficiency of the heterogeneous wireless multimedia broadcast receivers. This joint optimization is achieved by grouping the users based on their device capabilities and estimated channel conditions experienced by them and broadcasting adaptive content to these groups. The adaptive multimedia content is obtained by using scalable video coding (SVC) with optimal source encoding parameters resulted from an innovative cooperative game. Energy saving at user terminals results from using a layer-aware time slicing approach in the transmission stage. A trade-off between energy saving and QoE is observed, and is incorporated in the definition of a utility function of the players in the formulated heterogeneous user composition and physical channel aware game. An adaptive modulation and coding scheme is also optimally incorporated in order to maximize the reception quality of the broadcast receivers, while maximizing the network broadcast capacity. Compared to the conventional broadcast schemes, the proposed framework shows an appreciable improvement in QoE levels for all users, while achieving higher energy-savings for the energy constrained users.
IEEE Transactions on Broadcasting, 2000
The continuing growth in video content exchanged by mobile users creates challenges for the netwo... more The continuing growth in video content exchanged by mobile users creates challenges for the network service providers in terms of supporting seamless multimedia delivery at high quality levels, especially given the existing wireless network resources. A solution which deals with this mobile broadband data growth is to make use of multiple networks supported by diverse radio access technologies. This multi-access solution requires innovative network selection mechanisms to keep the mobile users "always best connected" anywhere and anytime. Additionally, there is a need to develop energy efficient techniques in order to reduce power consumption in nextgeneration wireless networks, while meeting user quality expectations. In this context, this paper proposes an Enhanced