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  • 1. Erman, David
    et al.
    Yao, Yong
    Vogeleer, Karel De
    Popescu, Adrian
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Evaluation of Swarm Video Streaming2010Konferansepaper (Fagfellevurdert)
    Abstract [en]

    IPTV has been hailed as a “killer app'' of the Internet for a long time, but it has yet to really make a major breakthrough, due to various technical and political reasons. The recent influx of community-driven video distribution has re-actualized the research into efficient distribution methods for streaming video. In this paper, we suggest a number of modifications and extensions to the BitTorrent distribution and replication system to make it suitable for use in providing a streaming video delivery service, and implement parts of these in a simulator. Also, we report on a simulation study as well as a large-scale real-world study of the extensions on PlanetLab. Results show that BitTorrent can be used as a bandwidth-efficient alternative to traditional IPTV solutions.

  • 2.
    Fiedler, Markus
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    Popescu, Adrian
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    Yao, Yong
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    QoE-aware sustainable throughput for energy-efficient video streaming2016Inngår i: Proceedings - 2016 IEEE International Conferences on Big Data and Cloud Computing, BDCloud 2016, Social Computing and Networking, SocialCom 2016 and Sustainable Computing and Communications, SustainCom 2016 / [ed] Cai Z.,Luo G.,Cheng L.,Angryk R.,Li Y.,Bourgeois A.,Song W.,Cao X.,Krishnamachari B., IEEE, 2016, s. 493-500Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This work motivates and details the concept of QoE-aware sustainable throughput in the area of video streaming. Sustainable throughput serves as a mean to compare video streaming solutions in terms of Quality of Experience (QoE) and energy efficiency (EE). It builds upon the QoE Provisioning-Delivery Hysteresis (PDH) and denotes the maximal throughput at which QoE deteriorations can be kept below a quantifiable level, which in turn allows to compare the EE of different video streaming solutions on QoE-fair grounds. In this work, we particularly focus on delivery problems stemming from outage-prone links, as they are typical for mobile systems. Well-adapted to the nature of the video-associated data streams and disturbances, a stochastic fluid flow model is used that allows for straightforward calculation of sustainable throughput values. We also discuss the application of the sustainable throughput for comparisons among different streaming solutions and their offered QoE and EE, respectively.

  • 3.
    Guo, Yang
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kreativa teknologier. Blekinge institute of Technology.
    Bai, Guohua
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kreativa teknologier. Blekinge institute of Technology.
    Yao, Yong
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik. Blekinge institute of Technology.
    A new Software Framework for Heterogeneous Knowledge Sharing in Healthcare system2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Today’s demand for healthcare is dramatically increasing as the factor of the aging population and expectations growing during the past few years. This leads to the need of substantial healthcare services with innovative technologies developed from both industry and academia. Designing an efficient healthcare system is however a sophisticated process due to different research issues with the requirement for the provision of high-quality healthcare services. Connected to this requirement, the focus of many studies done so far is widely laid on a well-known problem called knowledge sharing. In recent years, knowledge sharing raises as one of the most demanding applications with references to the dynamic inter-activity among different healthcare actors and the complex data structures involved in this application. Suitable solution approach to knowledge sharing can enhance the efficiency of healthcare delivery, and thus improving the quality of healthcare services. The corresponding development tasks can be accomplished by using different methodologies such as analytical approaches, simulation experiments and practical measurements on the real healthcare system.In our work, the problem of heterogeneous knowledge sharing in the healthcare system is considered. Here, the heterogeneous aspect is expressed in terms ofdifferent healthcare actors and the associated characterizations. To do this, we suggest a new software framework, which mainly consists of three components. The first component is about the ontology based activity theory, which is used to scientifically represent the healthcare actors together with their relationships and interactions. The second component refers to an overlay decision maker, which is responsible for dealing with the decision-making activities such as appointment scheduling. Its advantage is to jointly consider various healthcare parameters and different algorithms for decision-making purposes. Based on these two components, the third component provides the theoretical models to conduct the numerical analysis and performance evaluation on the particular healthcare service.

  • 4.
    Guo, Yang
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kreativa teknologier. Blekinge institute of Technology.
    Yao, Yong
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    On Performance of Prioritized Appointment Scheduling for Healthcare2017Inngår i: TRANSACTIONS ON EMERGING TELECOMMUNICATIONS TECHNOLOGIESArtikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Designing the appointment scheduling is a challenging task for the development of healthcare system. The efficient solution approach can provide high quality of healthcare service between care providers (CP) s and care receivers (CR) s. In this paper, we consider the healthcare system with the heterogeneous CRs in terms of urgent and routine CRs. Our suggested model assumes that the system gives the service priority to the urgent CRs by allowing them to interrupt the ongoing routine appointments. An appointment handoff scheme is suggested for the interrupted routine appointments, and thus the routine CRs can attempt to re-establish the appointment scheduling with other available CPs. With these considerations, we study the scheduling performance of the system by using Markov chains based modeling approach. The numerical analysis is reported and the simulation experiment is conducted to validate the numerical results.

  • 5.
    Guo, Yang
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datavetenskap. Blekinge institute of Technology.
    Yao, Yong
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datavetenskap.
    On Performance of Prioritized Appointment Scheduling for Healthcare2019Inngår i: Journal of Service Science and Management, ISSN 1940-9893, E-ISSN 1940-9907, Vol. 12, s. 589-604Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Designing the appointment scheduling is a challenging task for the development of healthcare system. The efficient solution approach can provide high-quality healthcare service between care providers (CP)s and care receivers (CR)s. In this paper, we consider the healthcare system with the heterogeneous CRs in terms of urgent and routine CRs. Our suggested model assumes that the system gives the service priority to the urgent CRs by allowing them to interrupt the ongoing routine appointments. An appointment handoff scheme is suggested for the interrupted routine appointments, and thus the routine CRs can attempt to re-establish the appointment scheduling with other available CPs. With these considerations, we study the scheduling performance of the system by using the Markov chains based modeling approach. The numerical analysis is reported and the simulation experiment is conducted to validate the numerical results.

  • 6.
    Guo, Yang
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kreativa teknologier. Blekinge institute of Technology.
    Yao, Yong
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Bai, Guohua
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kreativa teknologier.
    eHASS: A Smart Appointment Scheduling System for eHealth2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In the eHealth system, the appointment scheduling is an important task for the delivery of healthcare service among different healthcare actors. The key procedure is to do the decision making on the selection of suitable appointments between the care providers and the care receivers. The appointment decisionis a sophisticated problem in terms of how to efficiently deal with various parameters of involved healthcare actors. To solve this problem, we suggest a smart system called eHealth Appointment Scheduling System (eHASS). eHASS takes into account both heterogeneous aspects and interoperability requirements of eHealth system. As such, eHASS is capable of jointly considering various appointment characterizations and decision making algorithms for conducting appointment scheduling. The paper reports the eHASS architecture as well as the related work-in-progress.

  • 7.
    Guo, Yang
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kreativa teknologier.
    Yao, Yong
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    Bai, Guohua
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kreativa teknologier.
    On Enhancement of Inter-Activity for Knowledge Sharing in eHealth2016Inngår i: 2016 INTERNATIONAL CONFERENCE ON COMMUNICATIONS (COMM 2016), IEEE, 2016, s. 247-250Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Today, knowledge sharing raises as an important issue that challenges for the eHealth management system. It becomes one of the most demanding applications with references to the dynamic inter-activities among different health actors and the complex data structures involved in this application. In this paper, we suggest an activity theory based ontology model to scientifically represent various health actors in the eHealth system. The goal of the suggest model is to enhance the inter activities among these health actors for the efficient knowledge sharing purposes. We also develop a prototype software system based on the suggested ontology model. The survey results collected from the system users show the feasibility of the developed software system.

  • 8.
    Komu, Miika
    et al.
    Ericsson Res, FIN.
    Morabito, Roberto
    Ericsson Res, FIN.
    Kauppinen, Tero
    Ericsson Res, FIN.
    Kjallman, Jimmy
    Ericsson Res, FIN.
    Yao, Yong
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    Power Consumption in Remote Gaming: an Empirical Evaluation2016Inngår i: 2016 IEEE Conference on Computer Communications Workshops (INFOCOM WKSHPS), IEEE, 2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The thin-client approach for gaming is becoming more popular. For instance, Nvidia Shield, Valve Steam and Shinra technologies have offerings based on the concept. In remote cloud gaming, the game is being executed and processed in the cloud while the user receives a video and audio stream of the game, in a very similar way as with remote desktop clients. At the same time, clouds are moving towards the end-users as "edge clouds" with different standardization bodies, such Open Mobile Edge Cloud and Open Fog Consortium, giving momentum for the efforts. Were remote gaming approaches to utilize edge clouds, the games could be played without installing any infrastructure at the homes of end-users while keeping network delays to the latency-sensitive games low. While waiting for such edge-cloud deployments to substantiate, even regional clouds could be utilized for the purpose. In such environments, remote cloud gaming can already now be utilized by game companies as an alternative to traditional download-and-install games in order to support, e.g., anti-piracy protection. While the incentives for the game companies are relatively clear, the end-user experience has been investigated mainly from the viewpoint of latency. In this paper, we fill a research gap related to energy efficiency by showing that mobile phone users can save between 12 and 32 % power by utilizing remote gaming instead of playing with a native app. Our prototype is based on GamingAnywhere open-source software for which we have also integrated a gamepad for easier controls. We show power measurements both with a 2D and 3D games, and also additional measurements with a smart TV-stick.

  • 9.
    Ngoga, Said Rutabayiro
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Yao, Yong
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Popescu, Adrian
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    A Simple Time-based Threshold Strategy for Dynamic Spectrum Access2012Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In dynamic spectrum access networks, the unused licensed spectrum of primary users (PU) is opened to unlicensed secondary user (SU) for improving spectrum efficiency. The problem we study in this paper is to maximize the SU throughput while guaranteeing PU performance. We design a simple time-based threshold strategy to maximize the SU throughput while guaranteeing the PU performance by learning directly from the interaction with PU environment. At a given time, the SU decides if it should transmit and if so to protect the PU performance. It is observed that such strategies perform closely to the strategy optimized based on prior knowledge about PU traffic models. Simulations are used for performance evaluation.

  • 10.
    Ngoga, Said Rutabayiro
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Yao, Yong
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Popescu, Adrian
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Beacon-Enabled Cognitive Access for Dynamic Spectrum Access2012Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In dynamic spectrum access networks, the unused licensed spectrum used by primary users (PU) is opened to unlicensed secondary users (SU) for improving spectrum efficiency. We design a simple time-based threshold policy for collective protection of PUs, enabled by an out-of-band channel. In particular, multiple SUs may be widely distributed in a geographic location. The interference that collocated SUs cause to each other, termed self-interference, becomes a major source that may degrade the SUs communication performance. We establish an analytical framework for carrier sense multiple access (CSMA) based coexistence mechanisms when integrated into a family of time based threshold policies, and study its performance though theoretical analysis.

  • 11.
    Popescu, Adrian
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Yao, Yong
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Fiedler, Markus
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för teknik och estetik.
    Ducloux, Xavier
    Harmonic, FRA.
    Video Distribution Networks: Models and Performance2018Inngår i: Greening Video Distribution Networks: Energy-Efficient Internet Video Delivery / [ed] Adrian Popescu, Springer, 2018, s. 227-Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    The creation, distribution and delivery of video content is a sophisticated process with elements like video acquisition, preprocessing and encoding, content production and packaging as well as distribution to customers. IP networks are usually used for the transfer of video signals. The treatment of video content is also very complex, and we have a multidimensional process with elements like content acquisition, content exchange and content distribution. The focus of the chapter is on the presentation of models that can be used to characterize the main elements in a video distribution chain. These models are about video coding and compression, video streaming, video traffic models, energy consumption models, system performance, concepts of performance optimization and QoE- and energy-optimal streaming.

  • 12.
    Popescu, Adrian
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Yao, Yong
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Ilie, Dragos
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Video Distribution Networks: Architectures and System Requirements2018Inngår i: Greening Video Distribution Networks: Energy-Efficient Internet Video Delivery / [ed] Adrian Popescu, Springer, 2018Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    The creation of video content and its distribution over the Internet Protocol (IP) are sophisticated processes that follow a chain model from the acquisition of the video source, production and packaging, transport, and finally distribution to viewers. Video distribution networks refer to several parts, namely content contribution, primary distribution, secondary distribution, and video consumers. The focus of the chapter is on the presentation of video distribution systems over IP, categories of architectural solutions as well as a short presentation of several important applications associated with video distribution networks.

  • 13.
    Popescu, Alexandru
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Yao, Yong
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Fiedler, Markus
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    On Mobility Generated Signaling in Cognitive Radio Network Clusters2013Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The rapid migration towards wireless connectivity means that the radio spectrum must be efficiently utilized to conserve capacity and to avoid overcrowding, particularly in densely populated areas. Towards this goal, cognitive radio technology is a key concept. The basic idea is to allow unlicensed users access to licensed spectrum, under the condition that the interference perceived by the licensed users is minimal. A novel architecture designed and developed at the application layer has been suggested by researchers at Blekinge Institute of Technology for the management of cognitive radio networks. Emphasizing on signaling facilities in this architecture and common control channel dimensioning aspects, the paper reports on simulation results regarding node mobility for a particular network model. To reduce the energy consumption of mobile devices, innovative signaling strategies are a very important topic to consider in novel mobile system architectures.

  • 14.
    Popescu, Alexandru
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    Yao, Yong
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    Fiedler, Markus
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    Popescu, Adrian
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    A Management Architecture for Multimedia Communication in Cognitive Radio Networks2015Inngår i: Multimedia over Cognitive Radio Networks: Algorithms, Protocols, and Experiments / [ed] Hu, F; Kumar, S, CRC Press, 2015, s. 3-31Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 15.
    Popescu, Alexandru
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Yao, Yong
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Fiedler, Markus
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Popescu, Adrian
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Communication Mechanisms for Cognitive Radio Networks2013Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Comprehensive communication in cognitive radio networks is an important research topic within the scope of empowering cognitive radio functionality in beyond-4G mobile networks. Providing communication for secondary users without interference with primary users is an ambitious task, which requires innovative management architecture designs and routing solutions. Operational challenges such as opportunistic spectrum access, solving problems related to spectrum and network heterogeneities and requests for the provisioning of Quality-of-Service to different applications must be resolved. As part of a novel management architecture, the paper advances a new approach to end-to-end communication in cognitive radio networks based on combining ad-hoc algorithms with spectrum mobility algorithms.

  • 16.
    Popescu, Alexandru
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    Yao, Yong
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    Fiedler, Markus
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    Popescu, Adrian
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    Network Architecture to Support Multimedia over CRN2014Inngår i: Multimedia over Cognitive Radio Networks: Algorithms, Protocols, and Experiments / [ed] Hu, Fei; Kumar, Sunil, CRC Press , 2014Kapittel i bok, del av antologi (Fagfellevurdert)
  • 17.
    Rutabayiro Ngoga, Said
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Yao, Yong
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Popescu, Adrian
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    On Multi-channel Opportunistic Access in Heterogeneous Cognitive Radio Networks2013Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In the paper, we study optimal transmission strategies in multi-channel opportunistic spectrum access (OSA) networks where one secondary user (SU) opportunistically accesses multiple orthogonal channels of primary users (PUs) under a continuous time Markov chain modeling of the channel occupancy by the PUs. Referred to as tunable threshold strategy, at a given time the SU chooses one channel of a given PU, decides if it should transmits or not and if so it protects the PU of this channel. To be operational, such a structure depends on the capability of the SU radio front-end to perform channel sensing. We consider one scenario where the SU node can simultaneously sense multiple channels and another scenario where the SU node can sense only one channel at a time. For each scenario, we develop the structure of the optimal transmission strategy and analyse the performance. We show that the optimal transmission strategy can be implemented using a simple tunable threshold algorithm.

  • 18.
    Yao, Yong
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    A Software Framework for Prioritized Spectrum Access in Heterogeneous Cognitive Radio Networks2014Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Today, the radio spectrum is rarely fully utilized. This problem is valid in more domains, e.g., time, frequency and geographical location. To provide an efficient utilization of the radio spectrum, the Cognitive Radio Networks (CRNs) have been advanced. The key idea is to open up the licensed spectrum to unlicensed users, thus allowing them to use the so-called spectrum opportunities as long as they do not harmfully interfere with licensed users. An important focus is laid on the limitation of previously reported research efforts, which is due to the limited consideration of the problem of competition among unlicensed users for spectrum access in heterogeneous CRNs. A software framework is introduced, which is called PRioritized Opportunistic spectrum Access System (PROAS). In PROAS, the heterogeneity aspects of CRNs are specifically expressed in terms of cross-layer design and various wireless technologies. By considering factors like ease of implementation and efficiency of control, PROAS provides priority scheduling based solutions to alleviate the competition problem of unlicensed users in heterogenous CRNs. The advanced solutions include theoretical models, numerical analysis and experimental simulations for performance evaluation. By using PROAS, three particular CRN models are studied, which are based on ad-hoc, mesh-network and cellular-network technologies. The reported results show that PROAS has the ability to bridge the gap between research results and the practical implementation of CRNs.

  • 19.
    Yao, Yong
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    A Spectrum Decision Support System for Cognitive Radio Networks2012Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Cognitive Radio Networks (CRNs) offer a promising capability of alleviating the problem of spectrum insufficiency. In CRNs, the licensed spectrum channels are either exclusively reserved for licensed users or temporarily used by unlicensed users. The requirement for unlicensed users is to not harmfully impair the licensed users transmissions. Because of this, the unlicensed users must solve the task to decide which available channels should be selected. The selection process is often referred to as spectrum decision, with the aim to optimize the transmission performance of unlicensed users. A support system for CRNs is introduced, which is called Spectrum Decision Support System (SDSS). SDSS provides an intelligent spectrum decision strategy that integrates different decision making algorithms and takes into account various channel characterization parameters. The objective is to develop a scientific framework for decision making in CRNs, which involve theoretical analysis, simulation evaluation and practical implementation. Three important components of SDSS are discussed: 1) setting up an overlay decision maker, 2) prediction based spectrum decision strategy and 3) queuing modeling of CRNs. The reported results indicate the feasibility of the suggested algorithms.

  • 20. Yao, Yong
    et al.
    Erman, David
    PlanetLab Automatic Control System2010Konferansepaper (Fagfellevurdert)
    Abstract [en]

    PlanetLab provides a global scale environment for network research. It consists of numerous controllable computer nodes. However, due to that these nodes are deployed in various network domains, there exist experimental issues, regarding network latency, resource utilization, and unpredictable behaviors of nodes. Experimenters need to pay much attention to manually adjusting their selected nodes during the whole experimental process. PLACS is a novel tool system based on PlanetLab, and composed of node selection node management. It can intelligently and automatically coordinate the involved elements, including PlanetLab nodes, experimental programs and experimenter requirements. In this article, the corresponding mechanism functionalities and implementation designs for development are presented.

  • 21. Yao, Yong
    et al.
    Erman, David
    Popescu, Adrian
    Spectrum Decision for Cognitive Radio Networks2011Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Cognitive Radio Networks (CRNs) are a key technology suggested to be part of 4G and beyond. The fundamental concept is to let Secondary Users (SUs) have temporal free access to spectrum bands not occupied by Primary Users (PUs). Since SUs are not allowed to cause harmful interference to PUs, SUs need to select the most available spectrum bands for access, also known as spectrum decision. In the paper, we suggest a middleware called Spectrum Decision Support System (SDSS) abstractly illustrated. The goal of SDSS is to combine the different decision methods together and to make intelligent band selection based upon partial characterizations of CRNs

  • 22.
    Yao, Yong
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Ngoga, Said Rutabayiro
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Erman, David
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Popescu, Adrian
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Competition-Based Channel Selection for Cognitive Radio Networks2012Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In cognitive radio networks, unlicensed users need to learn from environmental changes. This is a process that can be done in a cooperative or non-cooperative manner. Due to the competition for channel utilization among unlicensed users, the non-cooperative approach may lead to overcrowding in the available channels. This paper is about a fuzzy-logic based decision making algorithm for competition-based channel selection. The underlying decision criterion integrates both the statistics of licensed users' channel occupancy and the competition level of unlicensed users. By using such an algorithm, the unlicensed user competitors can achieve an efficient sharing of the available channels. Simulation results are reported to demonstrate the performance and effectiveness of our suggested algorithm.

  • 23.
    Yao, Yong
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Ngoga, Said Rutabayiro
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Erman, David
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Popescu, Adrian
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Performance of Cognitive Radio Spectrum Access with Intra- and Inter-Handoff2012Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Opportunistic spectrum access (OSA) is a technology that allows unlicensed users to access spectrum holes and to provide so efficient use of radio resources. Most of the studies done on OSA focus on the situation when the unlicensed user performs the spectrum handoff only within a single cognitive radio network (so-called intra-handoff). In this paper, we consider the users (licensed or unlicensed) to be able to do inter-handoff among different cognitive radio cells as well. The cells provide priority to inter-handoff users. By considering multiple cells being in steady-state, the arrival rates of inter-handoff users are determined. We study the OSA performance of unlicensed users under both intra- and inter-handoff schemes, with respect to the blocking and forced-termination probabilities of unlicensed users as well as the unlicensed user service-completion and inter-handoff throughputs. Our Markov chain based numerical analysis is validated by simulation experiments.

  • 24.
    Yao, Yong
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Ngoga, Said Rutabayiro
    Popescu, Adrian
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    A System for Spectrum Decision in Cognitive Radio Networks2012Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In Cognitive Radio (CR) networks, licensed radio channels are allowed to be used by Secondary Users (SUs) as long as SUs do not harmfully impair the transmission of Primary Users (PUs). Therefore, a crucial task for SUs is to decide which available channel should be selected, the so-called spectrum decision. To provide intelligent spectrum decision strategy to SUs, we suggest a system called Spectrum Decision Support System (SDSS). SDSS takes into account both heterogeneity aspects and interoperability requirements of CR networks. By this, SDSS is capable of jointly considering various channel characterizations and different decision making algorithms for doing spectrum decision. The paper is reporting the SDSS architecture as well as the related work-in-progress.

  • 25.
    Yao, Yong
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Ngoga, Said Rutabayiro
    Popescu, Adrian
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Cognitive Radio Spectrum Decision Based on Channel Usage Prediction2012Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The paper is about a new strategy suggested for spectrum decision in Cognitive Radio (CR) networks. By jointly considering sensing error, Secondary Users (SUs) competition and SUs transmission collision, a new parameter called Channel Usage State (CUS) is introduced. For a particular channel, we predict the respective probabilities of occurrence of CUS states by using the LeZi-update scheme. We also adopt a fuzzy comparison algorithm to combine the prediction results as a joint value. The largest joint value is associated with the most available channel for access by SUs in the near future. By comparing with random channel access, the suggested strategy can improve SUs transmission throughput. This is demonstrated by the simulation evaluations.

  • 26.
    Yao, Yong
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    Popescu, Adrian
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    On Energy Consumption in Mobile Multimedia Networks with OpenFlow Switch2016Inngår i: 2016 INTERNATIONAL CONFERENCE ON COMMUNICATIONS (COMM 2016), IEEE, 2016, s. 309-312Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In mobile multimedia networks, the video flow usually operates in an end-to-end manner from Head-End to mobile terminals. However, measuring the energy consumption associated with a video flow is a sophisticated process due to the complexity related to this. In the paper, a theoretical measurement approach is suggested to estimate the energy consumption of a video flow through mobile multimedia networks enhanced with the support of OpenFlow switch. Two different power models are built up to compute the traffic related energy consumption at the network element side. The numerical derivation of these two theoretical models is presented.

  • 27.
    Yao, Yong
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Popescu, Adrian
    Blekinge Tekniska Högskola.
    On Energy Consumption in Mobile Multimedia Networks with OpwnFlow Switch2016Inngår i: International Conference on Communications (COMM), 2016, IEEE, 2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    With the advance of new wireless technologies and ubiquitous radio access, mobile multimedia is becoming a very important application for both service providers and end users. This also leads to different business models such as mobile television, mobile conferencing, and remote gaming. A Mobile Multimedia Network (MMN) generally refers to several parts, which are known as the video contribution, the network distribution and the mobile terminals. The video contribution is connected to the functions of generating and processing the video content, which is eventually transferred onto the network for further distribution to mobile terminals.

  • 28.
    Yao, Yong
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Popescu, Adrian
    Blekinge Tekniska Högskola.
    Fiedler, Markus
    Blekinge Tekniska Högskola.
    Ljung, Rickard
    Sony Mobile Communications, SWE.
    On the Performance of Video Streaming in Energy-Aware Wireless Mesh Networks2017Inngår i: European Conference on Networks and Communications (EuCNC) 2017, IEEE, 2017Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Mobile multimedia has today become a promising application for end users and service providers. With reference to the existing systems for mobile communications, this application further demands for solving several technical problems, especially regarding video streaming over wireless networks. An interesting approach is in form ofWireless Mesh Network (WMN) based networks, where the individual video flows operate in an end-to-end (e2e) manner along a particular networking scenario including several mesh routers. That means, a particular mesh router may be traversed by multiple video flows. This situation may become even more complicated in the case of a large amount of packet retransmissions, which may deteriorate the performance of video flows. To investigate this problem, a two-level Modulated Markov Poisson Process (MMPP) based queueing model is built up and the transport performance of e2e video streaming in WMN based mobile multimedia system is analysed. Four metrics are used to study the system performance, namely e2e throughput, e2e delay, e2e error-rate and traffic-related energy consumption. Numerical analysis and evaluation studies are done. Based on the reported results, two different solutions are suggested and discussed with regard to the trade-off among these metrics.

  • 29.
    Yao, Yong
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Popescu, Alexandru
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Ngoga, Said Rubatayiro
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Popescu, Adrian
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    On Prioritized Spectrum Access in Cognitive Radio Networks with Imperfect Sensing2013Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Cognitive Radio networks allow the unlicensed users to share the available spectrum opportunities. However, this demands for solving the problem of contention among multiple unlicensed user packets for transmission. In our paper, we consider the Opportunistic Spectrum Access model for packet transmission between two unlicensed users. We suggest a priority scheme for a unlicensed user to concurrently transmit different types of packets. Our scheme reserves a fixed number of queueing places in the buffer for the prioritized packets. We study the transmission performance under both the priority scheme and imperfect spectrum sensing, with respect to the blocking probabilities, average transmission delay and transmission throughput of unlicensed users packets. The Markov chain based numerical analysis is validated by simulation experiments. Our results show that the suggested priority scheme is able to enhance transmission throughput of unlicensed users packets, together with significant decreased average transmission delay and minor decreased total transmission throughput.

  • 30.
    Yao, Yong
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    Popescu, Alexandru
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    Popescu, Adrian
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    On Fuzzy Logic-Based Channel Selection in Cognitive Radio Networks2014Inngår i: Software-Defined and Cognitive Radio Technologies for Dynamic Spectrum Management / [ed] Kaabouch, Naima; Hu, Wen-Chen, Hershey, PA 17033, USA: IGI-Global , 2014Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    Cognitive radio networks are a new technology based on which unlicensed users are allowed access to licensed spectrum under the condition that the interference perceived by licensed users is minimal. That means unlicensed users need to learn from environmental changes and to take appropriate decisions regarding the access to the radio channel. This is a process that can be done by unlicensed users in a cooperative or non-cooperative way. Whereas the non-cooperative algorithms are risky with regard to performance, the cooperative algorithms have the capability to provide better performance. Our paper reports therefore a new fuzzy logic based decision making algorithm for channel selection. The underlying decision criterion considers statistics of licensed users channel occupancy as well as information about the competition level of unlicensed users. Our theoretical studies indicate that the unlicensed users can obtain an efficient sharing of the available channels. Simulation results are reported to demonstrate the performance and effectiveness of the suggested algorithm.

  • 31.
    Yao, Yong
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    Popescu, Alexandru
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    Popescu, Adrian
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    On prioritised opportunistic spectrum access in cognitive radio cellular networks2015Inngår i: European transactions on telecommunications, ISSN 1124-318X, E-ISSN 2161-3915, Vol. 27, nr 2, s. 294-310Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Cognitive radio (CR) networks allow secondary users (SUs) to opportunistically access licensed spectrum, thus providing efficient use of radio resources. Different studies carried out on CR networks have focused on the procedure of spectrum handoff of SUs such as the data transmission in a communication that can be carried out in different channels. In this paper, we consider cellular networks enhanced with facilities for CR communication where a user with a call in progress moves across neighbouring cells, that is, the so-called inter-cell handoff. Our model assumes that the cell gives priority to inter-cell handoff calls over the calls originating within it. A finite queue is used in every cell for SUs, and a fixed number of buffer slots are reserved for the inter-handoff SU calls. With these considerations, we study the transmission performance of SUs by using Markov chains-based modelling approach. The numerical analysis is validated by simulation experiments. We also suggest a fuzzy logic-based hybrid decision-making algorithm to select the best solution for inter-handoff prioritisation. The goal is to optimise the transmission performance of SUs by leveraging their requirements on service completion throughput and waiting time in each cell. Copyright © 2014 John Wiley & Sons, Ltd.

  • 32.
    Yong, Yao
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    Adrian, Popescu
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    On Prioritized Uplink Transmission in Cognitive Radio Mesh Networks2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In cognitive radio mesh networks, the unlicensed users are allowed to use spectrum opportunities under the restriction of protection of licensed users. The transmission operation of unlicensed users packets is typically done through multiple mesh routers. In the case of a large amount of packet retransmissions, the performance of the whole network system may degrade. To solve this problem, a queueing buffer based priority scheme for mesh routers is suggested. Based on this scheme, the uplink transmission performance of unlicensed users in cognitive radio mesh networks is studied under the condition of imperfect spectrum sensing. 

  • 33.
    Yong, Yao
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    Adrian, Popescu
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    On the Performance of Uplink Transmission in Cognitive Radio Mesh Networks2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In cognitive radio mesh networks, the unlicensed users are allowed to use spectrum opportunities under the restriction of protection of licensed users. The transmission operation of unlicensed users packets is typically done through multiple mesh routers. In the case of a large amount of packet retransmissions, the performance of the whole network system may degrade. To solve this problem, a queueing buffer based priority scheme for mesh routers is suggested. Based on this scheme, the uplink transmission performance of unlicensed users in cognitive radio mesh networks is studied under the condition of imperfect spectrum sensing. Numerical evaluation results show the feasibility and effectiveness of the suggested priority scheme. 

  • 34. Zhou, Kaibo
    et al.
    Liu, Gang
    Yao, Yong
    Popescu, Adrian
    A Mobility Management Solution for Simultaneous Mobility with mSCTP2011Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The paper is about mobile Stream Control Transmission Protocol (mSCTP) and the problems related to simultaneous mobility. Simultaneous mobility is when the both endpoints of a communication session are mobile and they move at about the same time. mSCTP works well in the case of non-simultaneous mobility where the SCTP association is established between a mobile endpoint and a stationary one. In the case of simultaneous mobility however, the probability of broken association may become high because both endpoints may suffer from losing address binding update. This is a consequence of the fact that the targeted addresses become unreachable. In this paper, we suggest a solution based on Host Name Address (HNA), together with pro-active Name Server, Address Handling Function (AHF) and Simultaneous Mobility Detection Function (SMDF) to eliminate this problem. Our preliminary results show that the performance of our solution is as good as for non-simultaneous mobility situation in terms of packet loss rate for low rate stream. On the other hand, the drawback is that some modifications to the current standard mSCTP are needed.

1 - 34 of 34
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