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  • 1.
    Debernardi, Nicolas
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Jäger,, Markus
    Laneri, Jean-Christophe
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Sraj, Malek
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Services Provisioning and Terminal Cooperation in User-Deployed Networks2006Ingår i: IEEE International Symposium on Personal, Indoor, and Mobile Radio Communications workshops, ISSN 2166-9570, E-ISSN 2166-9589Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Exploiting high-speed user-deployed Access Points (APs) in public infrastructures has been proposed as one of the candidate solutions for reducing the cost of future radio access. A disadvantage is that, due to lack of deployment coordination, these types of network are likely to provide only partial coverage. For this reason, the set of services that could be successfully provided in these networks might be rather limited. In this paper we present a novel framework for modeling non-interactive " infotainment" services with different degrees of "time criticality", and utilize it for investigating the user service perception in "spotty" coverage networks. In order to hide the infrastructure sparsity to the end users, the terminals are assumed equipped with software agents that can "opportunistically" pre-fetch information, on behalf of their users. This can be done when in contact with an AP, or, through a peer-to-peer file exchange with other terminal agents that have previously accessed the same information. In this paper, for different service types, the relationship between AP density and service perception is investigated. Furthermore, the impact of peer-to-peer terminal cooperation is evaluated in respect to both infrastructure requirements and content access delay. The results show that already with moderate AP densities, user-deployed networks deliver acceptable service perception, especially for services with low time criticality. Furthermore, whenever a "critical" mass of users shares common interests, the adoption of a peer-to-peer exchange strategy brings the significant gains of infrastructure reduction and/or improved service perception.

  • 2.
    Devlic, Alisa
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Kamaraju, Pavan
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Segall, Zary
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Tollmar, Konrad
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    QoE-aware optimization for video delivery and storage2015Ingår i: 2015 IEEE 16th International Symposium on "A World of Wireless, Mobile and Multimedia Networks" (WoWMoM) 2015, Boston, MA, USA, 2015, s. 1-10Konferensbidrag (Refereegranskat)
    Abstract [en]

    The explosive growth of Over-the-top (OTT) online video strains capacity of operators’ networks, which severely threatens video quality perceived by end users. Since video is very bandwidth consuming, its distribution costs are becoming too high to scale with network investments that are required to support the increasing bandwidth demand. Content providers and operators are searching for solutions to reduce this video traffic load, without degrading their customers’ perceived Quality ofExperience (QoE). This paper proposes a method that can programmatically optimize video content for desired QoE accordingto perceptual video quality and device display properties, while achieving bandwidth and storage savings for content providers, operators, and end users. The preliminary results obtained with Samsung Galaxy S3 phone show that up to 60% savings can be achieved by optimizing movies without compromising the perceptible video quality, and up to 70% for perceptible, but not annoying video quality difference. Tailoring video optimization to individual user perception can provide seamless QoE delivery across all users, with a low overhead (i.e., 10%) required to achieve this goal. Finally, two applications of video optimization: QoE-aware delivery and storage, are proposed and examined.

  • 3.
    Devlic, Alisa
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Kamaraju, Pavan
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Segall, Zary
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Tollmar, Konrad
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Towards QoE-aware adaptive video streaming2016Ingår i: 2015 IEEE 23rd International Symposium on Quality of Service (IWQoS), IEEE, 2016, s. 75-76, artikel-id 7404713Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper describes a novel QoE-aware adaptive video streaming method that enhances the viewing experience on mobile devices and reduces cellular network bandwidth consumed by Dynamic Adaptive Streaming over HTTP (DASH) by considering perceptual video quality and data rate channel conditions in the bitrate adaptation process. By streaming an optimized video for the particular video quality and channel conditions toa mobile device, we can improve the worst video qualities causedby DASH streaming and reduce quality variations using fewer number of bits.

  • 4.
    Devlic, Alisa
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab). KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Kamaraju, Pavan
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Segall, Zary
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab). KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Tollmar, Konrad
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab). KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Energy consumption reduction via context-aware mobile video pre-fetching2012Ingår i: Proceedings - 2012 IEEE International Symposium on Multimedia, ISM 2012, IEEE , 2012, s. 261-265Konferensbidrag (Refereegranskat)
    Abstract [en]

    The arrival of smartphones and tablets, along with a flat rate mobile Internet pricing model have caused increasing adoption of mobile data services. According to recent studies, video has been the main driver of mobile data consumption, having a higher growth rate than any other mobile application. However, streaming a medium/high quality video files can be an issue in a mobile environment where available capacity needs to be shared among a large number of users. Additionally, the energy consumption in mobile devices increases proportionally with the duration of data transfers, which depend on the download data rates achievable by the device. In this respect, adoption of opportunistic content pre-fetching schemes that exploit times and locations with high data rates to deliver content before a user requests it, has the potential to reduce the energy consumption associated with content delivery and improve the user's quality of experience, by allowing playback of pre-stored content with virtually no perceived interruptions or delays. This paper presents a family of opportunistic content pre-fetching schemes and compares their performance to standard on-demand access to content. By adopting a simulation approach on experimental data, collected with monitoring software installed in mobile terminals, we show that content pre-fetching can reduce energy consumption of the mobile devices by up to 30% when compared to the on demand download of the same file, with a time window of 1 hour needed to complete the content prepositioning.

  • 5.
    Devlic, Alisa
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab). KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Segall, Zary
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab). KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Tollmar, Konrad
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab). KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Evaluation of energy profiles for mobile video prefetching in generalized stochastic access channels2014Ingår i: Mobile and Ubiquitous Systems: Computing, Networking, and Services: 10th International Conference, MOBIQUITOUS 2013, Tokyo, Japan, December 2-4, 2013, Revised Selected Papers, Springer, 2014, s. 209-223Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper evaluates the energy cost reduction of Over-The-Top mobile video content prefetching in various network conditions. Energy cost reduction is achieved by reducing the time needed to download content over the radio interface by prefetching data on higher data rates, compared to the standard on demand download. To simulate various network conditions and user behavior, a stochastic access channel model was built and validated using the actual user traces. By changing the model parameters, the energy cost reduction of prefetching in different channel settings was determined, identifying regions in which prefetching is likely to deliver the largest energy gains. The results demonstrate that the largest gains (up to 70%) can be obtained for data rates with strong correlation and low noise variation. Additionally, based on statistical properties of data rates, such as peak-to-mean and average data rate, prefetching strategy can be devised enabling the highest energy cost reduction that can be obtained using the proposed prefetching scheme.

  • 6.
    Hultell, Johan
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Zander, Jens
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Service Provisioning with Ad-Hoc Deployed High-Speed Access Points in Urban environments2005Ingår i: 2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2005, IEEE conference proceedings, 2005, Vol. 3, s. 2019-2023Konferensbidrag (Refereegranskat)
    Abstract [en]

     Exploiting user-deployed networks as part of a public infrastructure has been proposed as a concept to radically lower the cost of provisioning access and services in urban environments. An important question is how dense a network with spotty coverage has to be in order to support interesting services. In this paper1, we introduce a framework for evaluating the user-perceived performance for two service types, a time-critical news subscription service (involving streaming) and a more delay tolerant entertainment service ("web browsing"). The user terminals contain a memory cache and an "agent" that opportunistically downloads and stores relevant pieces of information as users walk close to the access points. Results show that above a critical access point density, that is still significantly lower than the one required for continuous coverage, the services start performing very well with little or no outdated information. In most studied scenarios, we are communication limited meaning that memory capacity is not a problem, but energy is.

  • 7.
    Hultell, Johan
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Zander, Jens
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Service Provisioning with Ad-hoc Deployed High-Speed Access Points in Urban Environments2005Konferensbidrag (Refereegranskat)
  • 8.
    Kamaraju, Pavan
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Segall, Zary
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    A novel paradigm for context-aware content pre-fetching in mobile networks2013Ingår i: 2013 IEEE Wireless Communications and Networking Conference (WCNC), IEEE Communications Society, 2013, s. 4534-4539Konferensbidrag (Refereegranskat)
    Abstract [en]

    The current content provision methods and associated pricing and business models are challenged by the traffic requirements anticipated for future 'data intensive' services. In order to deliver substantially higher peak rates operators will need to deploy a much denser infrastructure and/or acquire more spectrum, thus significantly increasing their CAPEX and OPEX and reducing revenues. To improve the utilization of available network resources this paper presents ActiveCast, a disruptive content delivery paradigm that supports opportunistic content pre-fetching by introducing semantic and context awareness in the currently 'agnostic' networking paradigm. The experimental investigations presented in the paper focus on mobile video provision and a content provider, integrated with Facebook and YouTube, has been developed and used to identify socially relevant content for a set of test users. Part of the studies presented in the paper aim at experimentally understanding the structure of the energy costs associated with pre-fetching and on defining a delivery strategy that allows controlling the amount of energy invested. A comparison between a centralized implementation, in which pre-fetching is coordinated by the mobile operators, and an Over-The-Top (OTT) implementation of ActiveCast are also presented. The results show that complementing the context information available at individual user terminals with traffic information, shared by mobile operators through the ActiveCast API, can substantially reduce the energy costs of content delivery, as compared with 'on demand' video streaming. Additionally, opportunistically exploiting connections with WiFi APs can amplify the gains already achievable by prefetching on wide area networks.

  • 9. Kumar, Pavan
    et al.
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Nandakumar, Vikrant
    Segall, Zary
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    A novel experimental framework to investigate context-aware solutions for opportunistic M2M content delivery2011Konferensbidrag (Refereegranskat)
  • 10.
    Lindström, Magnus
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Forwarding Incentives by Means of Resource Delegation and Rewards in Multihop Cellular Networks2005Ingår i: RVK05 - Radiovetenskap och kommunikation: Linköping 2005, 2005Konferensbidrag (Refereegranskat)
    Abstract [en]

    Multihop techniques have been shown to provide ameans to increase coverage and/or capacity in cellular net-works. The concept is, however, challenged by a lackof forwarding incentives. Studies of a scheme called Re-source Delegation and pricing based rewards, have shownthat multihop solutions can significantly increase operatorrevenue, user data rates and service appreciation while atthe same time lowering the interference level in the net-work; compared to classical cellular architectures.Previous work has focused on the gains on a systemlevel. In this paper1 we investigate the data rate gains on aper-user level and discuss some implementational aspects.In particular we study how a silent period associated withthe relay switching from receive to transmit mode affectsmultihopping performance.It is found that the larger part of the rate improvementsis attained by users far from the base stations. This in-dicates that resource delegation both increases the aver-age data rate and reduces the distance dependent spread inrates. It is also seen that the silent receive-transmit transi-tions of relays do not severely compromise the benefits ofresource delegation in a TDMA system.

  • 11.
    Lindström, Magnus
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster (Stängd 20120101), Kommunikationssystem, CoS (stängd 2012-01-01). KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster (Stängd 20120101), Kommunikationssystem, CoS (stängd 2012-01-01). KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Resource Delegation and Rewards to Stimulate Forwarding in Multihip Cellular Networks2005Ingår i: VTC 2005-Spring: 2005 IEEE 61st Vehicular Technology Conference, Proceedings, IEEE , 2005, nr 4, s. 2152-2156Konferensbidrag (Refereegranskat)
    Abstract [en]

    Multihop cellular networks that base the forwarding process on user terminals are challenged by a lack of forwarding incentive. In this paper 1, we present the novel concept of Resource Delegation which, applied in combination with pricing based rewards, guarantees both the separation of resources between originating transmitters and relays and the economic compensation of the energy investments of the relays. The results show that this strategy leads to the definition of a broad region of prices in which multihopping solutions can achieve the following advantages over classical single-hop architectures: operator's revenues and provided datarates increase significantly, the users' appreciation of the service is enhanced, and the average interference level of the network is lowered.

  • 12.
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Collaborative Information Revelation and Collusion in "Word-of Mouth" Access Selection Schemes2007Ingår i: 2007 IEEE 65TH VEHICULAR TECHNOLOGY CONFERENCE, 2007, s. 282-286Konferensbidrag (Refereegranskat)
    Abstract [en]

    "Word-of-Mouth", a novel scheme for sharing the service quality experienced with different local networks, is presented and evaluated as a distributed solution for performing user-initiated access selection in a multi-system scenario.

    If only partial information, about the different access alternatives, is available, by sharing and processing individually discovered information, terminal agents can collectively reveal otherwise concealed information and perform more informed access selection decisions. Introducing collusion mechanisms, between low performing networks and terminal agents, we investigate the robustness, of our distributed mechanism, to the dissemination of false information. In a scenario in which user-deployed APs have different degrees of backbone capacity limitation we investigate, if local operators can attract more traffic, by monetarily bribing terminal agents to transfer false information. Furthermore, we evaluate, under which conditions the prediction capability of our scheme can still support roaming access selection decisions that improve user service appreciation.

    The results show that if "enough" information, can be collected by independent sources, "economically rational" low performing APs can be effectively prevented from both concealing information and/or attempting to influence their reputation through collusive behavior.

  • 13.
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster, Kommunikationssystem, CoS.
    Context-based Resource Management and Architectures for Future Wide and Local Area Wireless Networks2010Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    In the last few years we have been witnessing the beginning of a revolution in the world of wireless communication. The recent launch of advanced smartphones in the mobile market has been welcomed by mobile operators as an opportunity to finally fulfill the promises of 3G and increase the uptake of mobile services. Driven by unprecedented user experience and flat rate pricing, the success of novel mobile platforms for accessing multimedia content and applications has gone far beyond the most optimistic of expectations. Data-hungry services are currently creating significant capacity limitations in many networks, and projections on future content consumption anticipate that with the next generation of mobile devices the stress on cellular infrastructures will increase. Rolling-out additional capacity is not the most profitable of solutions given the current cost structure of mobile infrastructures. Instead, a significant cost reduction can be achieved by revolutionizing the current content provision paradigm. Accordingly, this thesis proposes solutions for making future services and infrastructures more affordable. From an operator perspective, terminal-to-terminal information forwarding has the potential to increase both coverage and capacity, however it introduces opportunity costs and energy losses at the user side. Resource delegation, together with an energy reimbursement scheme, is presented in this thesis to induce user cooperation. The results show that this approach is successful in fostering significant cooperation among users and can create a simultaneous improvement in user utility, data rates and operator revenues. Opening up for public access privately deployed WLANs might radically lower the cost of wireless services. However, since these networks are deployed in an uncoordinated manner, only discontinuous coverage can be provided. To hide the sparsity of the infrastructure to the end-user perception we propose the adoption of opportunistic schemes for content pre-fetching. Results show that already with moderate AP densities a set of archetypical services, including web-browsing, can be provided with sufficient user perceived quality. Epidemic exchange of popular content, and inter-AP cooperation are also shown to further decrease the required AP density. Moreover, to support informed access selection decisions when performing vertical handovers to WLANs, we propose “Word-of-Mouth”, a reputation-based scheme for revealing the QoS of different networks. By epidemically exchanging grades on their experienced service quality, we show that terminal agents can collectively improve their decision making, avoiding selecting networks not meeting the required QoS. Context-based content delivery is presented in this thesis as means to improve the utilization of wireless resources in cellular systems. Since networks are typically dimensioned for peak hour traffic, the BSs are underutilized for significant portions of the day. By adopting context-based architectures, capable of opportunistically utilizing the instantaneous excess of resources for content pre-fetching, we show that a significant amount of additional traffic can be served in already existing networks. The gains introduced by this content provision paradigm over the current “on-demand” solutions are further expressed in terms of lower requirements on BS density, more users in the system and larger files served while reaching the same level of user experience.

  • 14.
    Lungaro, Pietro
    KTH, Tidigare Institutioner, Mikroelektronik och informationsteknik, IMIT.
    Cost/Performance Trade-offs of "Two-Layers" Ad Hoc Multihop Cellular Access Systems2004Ingår i: Proceedings of the fourth Scandinavian Workshop on Wireless Ad-hoc Networks, 2004Konferensbidrag (Refereegranskat)
    Abstract [en]

    Ad Hoc multihop cellular access is considered tobe a strong candidate for the next generation of public phonesystems. In this paper, we present a novel approach for solving the dimensioning problem of an ad hoc system capable of two hopstransmissions. In this respect, is presented and analyzed a method for comparing the expenditure levels, for deploying andrunning a cellular network, implemented through a multihoppingsystem or through a standard cellular solution selected as reference. In particular, we describe the conditions in which the proposed multihopping solution is feasible, and quantify the performance/cost trade-offs that are achievable. Numerical results show that the spectral efficiency of currently deployed single hop systems can almost be doubled, if the user terminals are capable of multihopping and the cell planning is performed so that a critical mass of user per cell can be guaranteed.

  • 15.
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Distributed and Centralized Mobility-Aware Caching Schemes for Collaborative Service Provision in User-Deployed Networks2007Ingår i: 66th IEEE Vehicular Technology Conference, 2007, s. 309-314Konferensbidrag (Refereegranskat)
    Abstract [en]

    Opening up to public access, a collection of user-deployed APs has the potential to reduce service costs and improve user service perception, especially for delay tolerant services. However, since the individual APs composing such a network are typically owned and operated by different users, the achievable performances are likely to be limited by the lack of coordination. By adopting an Inter AP communication Protocol (IAPP) that allows APs to collaborate in exchanging messages about the information requested by potentially incoming users, the APs are capable to start caching information, even before the users reach their communication ranges. In a multi-user scenario, in which the backbone capacity limits the performances of the APs, a set of distributed backbone resource management schemes, differing in their degrees of collaboration between APs and their mobility-awareness, are proposed and evaluated in respect to both a centralized caching server solution and a non cooperative scheme. The results show that, at the cost of increased memory requirements, collaborative caching brings significant improvements to both backbone capacity utilization and average user rates, as compared to the non cooperating scheme. At the same time, we show that for a centralized server solution to outperform our collaborative caching scheme, the central server needs to have a backbone capacity comparable to sum of the capacities of the individual APs deployed in the service area.

  • 16.
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster, Kommunikationssystem, CoS.
    Self-organization, cooperation and control distribution in wide and local area networks2007Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    To support the future requirements on wireless systems in an affordable manner it is commonly believed that multiple radio access technologies have to be combined. These technologies can be deployed by a single operator or, even, be managed by different competing operators. In order to cope with the increased complexity of such a multifaced wireless environment it has been argued that a transfer of Radio Resource Management (RRM) functionalities towards the network edges (access ports and, ultimately, user terminals) may be beneficial. In addition to detecting varying system conditions in a faster manner this would also allow a more responsive service adaptation. In this thesis we evaluate a set of self-organizing regimes, all with the purpose of supporting the distribution of control at the edge node.

    Particular emphasis is put on the design of a mechanism for dynamically establishing cooperation between different network entities whether these are access ports or user terminals.

    Terminal cooperation by means of multihopping is considered in the context of service provision in cellular access systems. Previously the opportunity cost associated with sharing own bandwidth, and energy loss have been seen as a major obstacle for relaying other users’ traffic. To mitigate the effects of this selfish behavior the concept of resource delegation is introduced and evaluated in combination with a rewarding scheme designed for compensating the energy losses induced by forwarding. The results show that our proposed schemes not only are capable of fostering significant cooperation among users, but also to create a simultaneous improvement in user utility, data rates as well as in operator revenues.

    Opening up networks of user-deployed Access Points (APs) for service provision is considered a means to radically lower the cost of future wireless services. However, since these networks are deployed in an uncoordinated manner, only discontinuous coverage will be provided. The question of how dense these networks need to be, to deliver acceptable user perception, is investigated in this thesis for a set of archetypical services. The results show that already at moderate AP densities the investigated services can be provided with sufficient quality. Epidemic exchange of popular content and inter-AP cooperation are also shown to further decrease the required infrastructure density and improve the APs’ utilization respectively.

    As last contribution, “Word-of-Mouth”, a distributed reputation-based scheme, is investigated in the context of access selection in multi-operator environments. By exchanging information concerning the Quality of Service (QoS) associated with the different networks, terminal agents can collectively reveal the capabilities of individual networks. For a vertical handover scenario we show that our proposed scheme can reward access providers capable of ensuring some degrees of QoS. By introducing a model for collusion, between low performing APs and terminal agents, we show that our proposed scheme is also robust to the dissemination of false information.

  • 17.
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    "Word-of-Mouth" in Radio Access Markets2005Konferensbidrag (Refereegranskat)
    Abstract [en]

    Opening up interoperability between wide and local area networks seems to be a very promising solution for delivering improved user experience while reducing overall service costs. In a scenario, where a single operator owns different types of networks, QoS provision can be achieved by introducing complex multi-system resource management. On the contrary, if local area networks are deployed by different entities, due to the lack of both coordination and centralized RRM management, the experienced QoS may drastically fluctuate, ranging from SLAs in wide area, to only ''best effort" expectations in local area networks.

    In order for "nomadic" terminal agents to perform "informed" access selection decisions, we propose the adoption of "Word-of-Mouth" (WoM), a novel scheme for sharing, in a peer-to-peer fashion, information about the service quality experienced with different networks. The performances of our proposed WoM scheme have been evaluated for a file pre-fetching service, considering information characterized by various degrees of time criticality, when different RRM strategies are implemented in the local area networks. The results show that if a critical mass of terminal agents exchange experienced QoS information, the overall network selection decision is improved: terminal agents can estimate, on beforehand, which type of performances to expect with different candidate networks, and avoid to select those not satisfying service requirements. This, in turn brings two main positive effects: on one hand, user perceived performance is improved, and, on the other hand, the adoption of RRM strategies providing some degree QoS is incentivated.

  • 18.
    Lungaro, Pietro
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Beelen, Thomas
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Tollmar, Konrad
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Human-to-AI interfaces for enabling future onboard experiences2017Ingår i: AutomotiveUI 2017 - 9th International ACM Conference on Automotive User Interfaces and Interactive Vehicular Applications, Adjunct Proceedings, Association for Computing Machinery (ACM), 2017, s. 94-98Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents a novel platform for supporting humancentric design of future on-board user interfaces. This is conceived to facilitate the interplay and information exchange among onboard digital information systems, autonomous AI agents and human passengers and drivers. Two Human-to-AI (H2AI) Augmented Reality (AR) interfaces, characterized by different degrees of immersivity, have been designed to provide passengers with intuitive visualization of information available in the AI modules controlling the car behavior. To validate the proposed usercentric paradigm, a novel testbed has been developed for assessing whether H2AI solutions can be effective in increasing human trust in self-driving cars. The results of our initial experimental studies, performed with several subjects, clearly showed that visualizing AI information brings a critical understanding of the autonomous driving processes, which in turn leads to a substantial increase of trust in the system.

  • 19.
    Lungaro, Pietro
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Segall, Zary
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Application-centric Content Delivery Schemes for Future Wireless Networks2011Ingår i: 2011 IEEE 22nd International Symposium On Personal Indoor And Mobile Radio Communications (PIMRC), New York: IEEE , 2011, s. 2128-2132Konferensbidrag (Refereegranskat)
    Abstract [en]

    The apps paradigm is rapidly changing the way in which content is transferred and consumed in mobile networks. Currently, the traffic loads generated by apps are mostly provided as Over-The-Top (OTT) services, essentially transparent to the cellular network operators, while some of the content is delivered and updated in user terminals through "background transmissions", without user intervention. With increasing traffic volumes, associated to richer content and more advanced devices, the apps paradigm might create severe system inefficiencies. In this paper we explore a number of apps based content delivery methods and investigate their performances on multiple relevant dimensions,such as: terminal energy consumption, time for accessing in-apps content and their impact on the user experience associated with other mobile data services. The proposed methods include opportunistic content pre-fetching and are characterized by different degrees of context-awareness. One approach considers only context information at the individual user terminals, while another one includes network context information and assumes that content distribution coordination is performed by the network operators. The results show that when one is increasing the numbers of apps, whose content needs to be simultaneously maintained updated, only the operator-driven approach can be feasible, mainly from an energetic perspective. However, for a small number of maintained apps, pre-fetching schemes are superior to standard "on-demand" content delivery solutions, suggesting that pre-fetching should be limited only to the subset of terminal apps with higher user access probabilities.

  • 20.
    Lungaro, Pietro
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Segall, Zary
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Zander, Jens
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    ActiveCast - a network and user aware mobile content delivery system2010Ingår i: Ubiquitous and Future Networks (ICUFN), 2010 Second International Conference on, IEEE , 2010, s. 309-313Konferensbidrag (Refereegranskat)
    Abstract [en]

    Most of the currently deployed networks are typically dimensioned considering the "peak hour" traffic demand. Opportunistically utilizing these "excess" resources might be an effective way for improving utilization and lowering the "production" costs. This paper is proposing and evaluating a novel concept, called ActiveCast, and the corresponding architecture for a network and user behavior aware mobile content delivery system. When considering real traffic measurements in urban scenarios we showed that the concept improves the resource utilization and allows serving significantly more users in a pre-existing network. Even with moderate amounts of reliable context information, ActiveCast have been shown to drastically improving both user quality of experience perception and network efficiency, as compared to conventional on-demand content delivery schemes.

  • 21.
    Lungaro, Pietro
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Segall, Zary
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Zander, Jens
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Context-aware RRM for opportunistic content delivery in cellular networks2010Ingår i: 3rd Int. Conf. on Communication Theory, Reliability, and Quality of Service, CTRQ 2010, Includes MOPAS 2010: 1st Int. Conf. on Models and Ontology-Based Design of Protocols, Architecture and Services, 2010, s. 175-180Konferensbidrag (Refereegranskat)
    Abstract [en]

    To opportunistically exploit excess resources avail-able at different times and locations we propose in this paperto include context aware information in the RRM schemesadopted in cellular networks. Both an user and a network centricapproaches to content pre-fetching are described and evaluatedfor different network dimensioning and service scenarios. Theobtained results show that for different levels of accuracyin predicting future content requests, operator controlled pre-fetching outperforms the user controlled approach, and that theformer can also bring robustness and significant cost reductionas compared to “classical” RRM schemes: the achieved level ofperformances can be mapped into a tri-dimensional gain regionwhere fewer BSs are needed, or more users can be served, orlarger files delivered per user, while maintaining a given levelof user-perceived service quality. Finally, considering also thedeployment of content caches at the BSs we show that the impactof backhaul limitations on experienced delays can be furthermitigated, when there are similar content interests among users.

  • 22.
    Lungaro, Pietro
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Segall, Zary
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Zander, Jens
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    ContextShift: a Model for EfficientDelivery of Content in MobileNetworks2010Ingår i: Wireless Communications & Networking Conference, 2010Konferensbidrag (Refereegranskat)
    Abstract [en]

    A context aware model for delivery of content inmobile networks is introduced and studied through simulation.The model is based on predictive knowledge of mobile userand mobile group behavior. The predictive behavior is relatedto consumption of mobile content on smart mobile terminals.The model proposes to change the time and the location ofthe delivery of predicted content consumption to optimize thewireless network utilization and to improve the user experience.Different content delivery strategies, considering pre-fetchingat the user terminals, caching at the base stations and multi-cast wireless transmissions are proposed and investigated. Thesimulation results show substantial gains in the content deliveryefficiency of cellular networks and improved user perceivedquality for a number of realistic network operation regimes.

  • 23.
    Lungaro, Pietro
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Segall, Zary
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Zander, Jens
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Predictive and Context-based Multimedia Content Delivery inFuture Cellular Networks2010Ingår i: 2010 IEEE 71ST VEHICULAR TECHNOLOGY CONFERENCE, 2010Konferensbidrag (Refereegranskat)
    Abstract [en]

    A context aware model for the delivery of contentin mobile networks is presented and studied through simulation.The proposed model is based on predictive knowledge of mobileuser behavior related to consumption of content on smartterminals. Content prediction is here exploited to change the timeand the location of content delivery, opportunistically utilizing theinstantaneously available excess of resources in the network. Thisis anticipated both to increase network utilization and to enhanceuser perceived service quality. However, since the accuracy of thecontext information, and associated content predictions, mighthave a significant impact on performances, our investigationshave been accounting for different content prediction capabilitiesas well as for various degrees of similarity in users’ contentrequests. The obtained results show that substantial gains bothin terms of wireless network efficiency and improved user serviceperception can be achieved, as compared to classical contentdelivery methods, for a number of realistic scenarios.

  • 24.
    Lungaro, Pietro
    et al.
    KTH.
    Sjöberg, Rickard
    Ericsson Res, Stockholm, Sweden..
    Valero, Alfredo Jose Fanghella
    KTH.
    Mittal, Ashutosh
    KTH.
    Tollmar, Konrad
    KTH.
    Gaze-Aware Streaming Solutions for the Next Generation of Mobile VR Experiences2018Ingår i: IEEE Transactions on Visualization and Computer Graphics, ISSN 1077-2626, E-ISSN 1941-0506, Vol. 24, nr 4, s. 1535-1544Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents a novel approach to content delivery for video streaming services. It exploits information from connected eye-trackers embedded in the next generation of VR Head Mounted Displays (HMDs). The proposed solution aims to deliver high visual quality, in real time, around the users' fixations points while lowering the quality everywhere else. The goal of the proposed approach is to substantially reduce the overall bandwidth requirements for supporting VR video experiences while delivering high levels of user perceived quality. The prerequisites to achieve these results are: (1) mechanisms that can cope with different degrees of latency in the system and (2) solutions that support fast adaptation of video quality in different parts of a frame, without requiring a large increase in bitrate. A novel codec configuration, capable of supporting near-instantaneous video quality adaptation in specific portions of a video frame, is presented. The proposed method exploits in-built properties of HEVC encoders and while it introduces a moderate amount of error, these errors are indetectable by users. Fast adaptation is the key to enable gaze-aware streaming and its reduction in bandwidth. A testbed implementing gaze-aware streaming, together with a prototype HMD with in-built eye tracker, is presented and was used for testing with real users. The studies quantified the bandwidth savings achievable by the proposed approach and characterize the relationships between Quality of Experience (QoE) and network latency. The results showed that up to 83% less bandwidth is required to deliver high QoE levels to the users, as compared to conventional solutions.

  • 25.
    Lungaro, Pietro
    et al.
    KTH, Tidigare Institutioner                               , Signaler, sensorer och system.
    Timus, Bogdan
    KTH, Tidigare Institutioner                               , Signaler, sensorer och system.
    Cost Analysis of Wireless Multihop Architectures2004Konferensbidrag (Refereegranskat)
    Abstract [en]

    Previous studies have shown that multihop techniques  can improve the capacity/coverage of a hybrid cellular  system, but the economic gain is still an open question. An  infrastructure cost analysis is performed in this paper on two  hybrid cellular architectures: one using terminals as relays and  one using fixed relays.

    For the first architecture we show numerical examples in which  the infrastructure cost is 20% to 40% higher when multihopping  is not used. The size of the gain depends on the density of relaying  terminals. For the second architecture the cost ratio between  deploying a new macro base station and deploying a wireless  relay. In the selected examples, the infrastructure cost is 25%  to 100% higher when multihopp is not used, for a cost ratio  between a macro base station and a relay varying from 20 to 34.

  • 26.
    Lungaro, Pietro
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS.
    Tollmar, Konrad
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS.
    Immersivemote: Combining foveated AI and streaming for immersive remote operations2019Ingår i: ACM SIGGRAPH 2019 Talks, SIGGRAPH 2019, Association for Computing Machinery (ACM), 2019, artikel-id 3329895Konferensbidrag (Refereegranskat)
    Abstract [en]

    Immersivemote is a novel technology combining our former foveated streaming solution with our novel foveated AI concept. While we have previously shown that foveated streaming can achieve 90% bandwidth savings, as compared to existing streaming solutions, foveated AI is designed to enable real-time video augmentations that are controlled through eye-gaze. The combined solution is therefore capable of effectively interfacing remote operators with mission critical information obtained, in real time, from task-aware machine understanding of the scene and IoT data.

  • 27.
    Lungaro, Pietro
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Tollmar, Konrad
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    QoE design tradeoffs for foveated content provision2017Ingår i: 2017 9th International Conference on Quality of Multimedia Experience, QoMEX 2017, Institute of Electrical and Electronics Engineers (IEEE), 2017, artikel-id 7965669Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper explores the key tradeoffs for the design and optimization of eye-gaze based content provision for video streaming services. The proposed end-to-end solution, called "foveated content provision", uses real-time information from connected eye-trackers to dynamically deliver optimized video frames, with higher resolution in areas corresponding to the users' fovea while lowering the quality at the periphery. In this novel approach, the main system constraint is the achievable latency (RTT) in the communication link between content servers and user clients. To cope with various latency levels, several design choices are presented, including varying the size of the high quality region or the resolution for the areas in the user's peripheral field of view. The paper presents a set of experimental results, obtained with real users via a novel event-driven experience sampling method, which is specifically developed to address Quality of Experience (QoE) in foveated content delivery. The results show that several operating points within the system parameter space allows to deliver high levels of QoE, even at latency levels comparable to current 4G networks.

  • 28.
    Lungaro, Pietro
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Tollmar, Konrad
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Mittal, Ashutosh
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Fanghella Valero, Alfredo
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Gaze- and QoE-aware video streaming solutions for mobile VR2017Ingår i: Proceedings of the ACM Symposium on Virtual Reality Software and Technology, VRST, Association for Computing Machinery , 2017Konferensbidrag (Refereegranskat)
    Abstract [en]

    This demo showcases a novel approach to content delivery for 360? video streaming. It exploits information from connected eye-trackers embedded in the users' VR HMDs. The presented technology enables the delivery of high quality, in real time, around the users' fixations points while lowering the image quality everywhere else. The goal of the proposed approach is to substantially reduce the overall bandwidth requirements for supporting VR video experiences while delivering high levels of user perceived quality. The network connection between the VR system and the content server is in this demo emulated, allowing users to experience the QoE performances achievable with datarates and RTTs in the range of current 4G and upcoming 5G networks. Users can further control additional service parameters, including video types, content resolution in the foveal region and background and size of the foveal region. At the end of each run, users are presented with a summary of the amount of bandwidth consumed with the used system settings and a comparison with the cost of current content delivery solutions. The overall goal of this demo is to provide a tangible experience of the tradeoffs among bandwidth, RTT and QoE for the mobile provision of future data intensive VR services.

  • 29.
    Lungaro, Pietro
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS.
    Tollmar, Konrad
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS.
    Saeik, Firdose
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS.
    Mateu Gisbert, Conrado
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Dubus, Gaël
    Demonstration of a low-cost hyper-realistic testbed for designing future onboard experiences2018Ingår i: Adjunct Proceedings - 10th International ACM Conference on Automotive User Interfaces and Interactive Vehicular Applications, AutomotiveUI 2018, Association for Computing Machinery, Inc , 2018, s. 235-238Konferensbidrag (Refereegranskat)
    Abstract [en]

    This demo presents DriverSense, a novel experimental platform for designing and validating onboard user interfaces for self-driving and remotely controlled vehicles. Most of currently existing vehicular testbeds and simulators are designed to reproduce with high fidelity the ergonomic aspects associated with the driving experience. However, with increasing deployment of self-driving and remotely controlled or monitored vehicles, it is expected that the digital components of the driving experience will become more relevant. That is because users will be less engaged in the actual driving tasks and more involved with oversight activities. In this respect, high visual testbed fidelity becomes an important pre-requisite for supporting the design and evaluation of future interfaces. DriverSense, which is based on the hyper-realistic video game GTA V, has been developed to satisfy this need. To showcase its experimental flexibility, a set of self-driving interfaces have been implemented, including Heads-Up Display (HUDs), Augmented Reality (ARs) and directional audio.

  • 30. Lungaro, Pietro
    et al.
    Tollmar, Konrad
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS.
    Saeik, Firdose
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS.
    Mateu Gisbert, Conrado
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Dubus, Gaël
    DriverSense: A hyper-realistic testbed for the design and evaluation of novel user interfaces in self-driving vehicles2018Ingår i: Adjunct Proceedings - 10th International ACM Conference on Automotive User Interfaces and Interactive Vehicular Applications, AutomotiveUI 2018, Association for Computing Machinery, Inc , 2018, s. 127-131Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents DriverSense, a novel experimental platform for designing and validating onboard user interfaces for self-driving and remotely controlled vehicles. Most of currently existing academic and industrial testbeds and vehicular simulators are designed to reproduce with high fidelity the ergonomic aspects associated with the driving experience. However, with increasing deployment of self-driving and remote controlled vehicular modalities, it is expected that the digital components of the driving experience will become more and more relevant, because users will be less engaged in the actual driving tasks and more involved with oversight activities. In this respect, high visual testbed fidelity becomes an important pre-requisite for supporting the design and evaluation of future onboard interfaces. DriverSense, which is based on the hyper-realistic video game GTA V, has been developed to satisfy this need. To showcase its experimental flexibility, a set of selected case studies, including Heads-Up Diplays (HUDs), Augmented Reality (ARs) and directional audio solutions, are presented. 

  • 31.
    Lungaro, Pietro
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Viedma, Cristobal
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Segall, Zary
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Kumar, Pavan
    An experimental framework to investigate context-aware schemes for content delivery2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    A novel experimental approach for investigating the performances of context-aware content delivery schemes is presented in this paper. An innovative testbed, capable of remotely controlling multiple terminals, injecting a wide range of traffic loads in real networks and monitoring different performance measures has been developed and utilized for quantifying both the energy costs and user perceived service quality associated with different context- aware content pre-fetching schemes. In the implementation proposed in this paper, the context information required for performing content pre-fetching is extracted and utilized by individual user terminals and does not require any support from mobile operators. The performances of pre-fetching are compared to those of an on-demand content delivery scheme, for both video streaming and file downloading services. The results shows that not only pre-fetching can increase user service appreciation by reducing the time needed to access the information, but it can also significantly lower the amount of energy consumed in user terminals for retrieving the content. Our experiments further indicate that in order to achieve these additional energy gains only limited content prediction capabilities are required, thus making pre-fetching a solid candidate for the provision of a wide range of content types and services in both wide and local area networks.

  • 32.
    Martinez Ballesteros, Luis Guillermo
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Cavdar, Cicek
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab).
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Segall, Zary
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Towards a Semantic-aware Radio Resource Management2013Ingår i: MOBILITY 2013, The Third International Conference on Mobile Services, Resources, and Users: Proceedings of The Third International Conference on Mobile Services, Resources, and Users, 2013, s. 16-19Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper semantic-aware model for radio resource management in wireless networks is introduced and studied through simulation. By semantic-awareness, the network can selectively manage the radio resource allocation based on the evaluation of transferred content, and its associated processing, and prioritize users that are close to experience interruptions, in order to improve the wireless resource utilization and the user’s Quality of Experience (QoE). Different radio resource management (RRM) strategies are proposed and investigated, considering buffer capacity at the terminals and the experience of the users in time while watching a video and waiting for resource allocation. The simulation results show that the users can reduce the total duration, frequency and length of the interruptions during a playback by applying semantic-awareness in the radio resource allocation, which might affect positively user’s QoE.

  • 33.
    Martinez Ballesteros, Luis Guillermo
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Segall, Zary
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Impact of semantic-aware radio resource management schemes on video streaming service2012Ingår i: Wireless and Mobile Computing, Networking and Communications (WiMob), 2012 IEEE 8th International Conference on, IEEE , 2012, s. 831-836Konferensbidrag (Refereegranskat)
    Abstract [en]

    Current wireless networks have no knowledge on the type and characteristics of the specific mobile services and contents they are providing (they are agnostic). On the other hand, associated to richer content and more advanced devices, improvement of Quality of Experience (QoE) levels perceived by each user looks as one of the main goals of the different actors in the telecommunication's ecosystem. In this respect, network awareness of the transferred content types and their quality requirements can be important to deliver them fulfilling user requirements while optimizing the utilization of network resources. In this paper, we explore the effect of including semantic knowledge in the radio resource management (RRM) schemes of cellular systems as a way to reach this balance for video streaming service. To make this possible, we propose a number of semantic-aware RRM schemes using information about the video playback's current status, and investigate their performances based on the reduction of the total time of interruptions (TTI) perceived by users when a video streaming content is played. The achieved results are compared to those of the standard agnostic scheme implemented in the cellular networks. The outcomes show that incorporating semantic-aware RRM schemes, more users can receive the content provided by a network within a tolerable level of TTI, while the number of users receiving High Definition (HD) videos can be increased, which in general terms might reduce the investment in infrastructure to fulfill users' requirements.

  • 34.
    Martinez Ballesteros, Luis Guillermo
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Segall, Zary
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Towards a Novel Resource Management Scheme in Wireless Networks based on Quality of Experience (QoE)2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper summarizes some of the initial research findings obtained in the SERMON project, funded by Wireless@KTH. The main focus of this paper is on video streaming transmission and the quantification of how much can be gained, in terms of user satisfaction and network resource utilization, by exploiting this semantic knowledge at network level. For this purpose, different QoE-centric RRM strategies are proposed and their performances evaluated in respect to a “classical” agnostic scheme, in a scenario where users have different QoE requirements for different content types and as a function of the device screen resolution during a live video streaming transmission.

  • 35.
    Saeik, Firdose
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS.
    Lungaro, Pietro
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS.
    Tollmar, Konrad
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS.
    Demonstration of Gaze-Aware Video Streaming Solutions for Mobile VR2018Ingår i: 2018 IEEE Conference on Virtual Reality and 3D User Interfaces (VR), 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    This demo features an embodiment of Smart Eye-tracking Enabled Networking (SEEN), a novel content delivery method for optimizing the provision of 360° video streaming. SEEN relies on eye-gaze information from connected eye trackers to provide high quality, in real time, in the proximity of users' fixations points, while lowering the quality at the periphery of the users' fields of view. The goal is to exploit the characteristics of the human vision to reduce the bandwidth required for the mobile provision of future data intensive services in Virtual Reality (VR). This demo provides a tangible experience of the tradeoffs among bandwidth consumption, network performances (RTT) and Quality of Experience (QoE) associated with SEEN's novel content provision mechanisms.

  • 36.
    Segall, Zary
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster (Stängd 20120101), Kommunikationssystem, CoS (stängd 2012-01-01). KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Eby, Chad
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster (Stängd 20120101), Kommunikationssystem, CoS (stängd 2012-01-01).
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster (Stängd 20120101), Kommunikationssystem, CoS (stängd 2012-01-01). KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Semantic Light2011Konferensbidrag (Refereegranskat)
  • 37.
    Segall, Zary
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth. CSEE, University of Maryland, Baltimore County, United States.
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster (Stängd 20120101), Kommunikationssystem, CoS (stängd 2012-01-01). KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Nandakumar, Vikrant
    Kumar, Pavan
    The Living Laboratory: a Holistic Approach for Understanding the Performance of Future Mobile Services and Networks2011Ingår i: 3rd International Conference on Ubiquitous and Future Networks, ICUFN 2011, 2011, s. 300-304Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents the Mobile Services Living Laboratory - a practical approach for evaluating service provision in cellular networks. Our approach promotes an end-to-end view of the system by providing an effective means to store information from both terminal and network sides, together with integrated mechanisms for retrieving feedback on user-perceived service quality. The current implementation of the Living Laboratory is described and evaluated. Further, we show how the Living Laboratory is used to investigate both the effectiveness of context-aware opportunistic content delivery schemes in cellular networks, and the coexistence between M2M and user-generated traffic.

  • 38.
    Tollmar, Konrad
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Valero, Alfredo Fanghella
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Mittal, Ashutosh
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Beyond foveal rendering: Smart eye-tracking enabled networking (SEEN)2017Ingår i: ACM SIGGRAPH 2017 Talks, SIGGRAPH 2017, Association for Computing Machinery (ACM), 2017, artikel-id 3085163Konferensbidrag (Refereegranskat)
    Abstract [en]

    Smart Eye-tracking Enabled Networking (SEEN) is a novel end-to-end framework using real-time eye-gaze information beyond state-of-the-art solutions. Our approach can effectively combine the computational savings of foveal rendering with the bandwidth savings required to enable future mobile VR content provision.

  • 39.
    Yavari, Ali
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Segall, Zary
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Network Efficient Resource Management for Mobile Video Streaming based on Quality of Experience2013Ingår i: 2013 International Conference on ICT Convergence (ICTC): , IEEE Communications Society, 2013, s. 654-659Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents a novel experimental approach to quantify the performances of Quality of Experience (QoE)- aware resource management scheme in mobile network. The main goal of this paper is to improve network efficiency by exploiting knowledge of QoE information associated with online video streaming services. The investigations considered in the paper are performed using an innovative test-bed, developed to assess network efficiency for the provision of online video services of different qualities. The QoE model used in the proposed QoEaware allocation scheme assumes a MOS-like grading function whose grades depend on both the duration of playtime interruption and the streaming video quality (resolution). The results show that the proposed resource management scheme can deliver more than 40 percent higher QoE to the users of the system as compared to current agnostic (not aware of QoE requirement and content characteristics) service models.

  • 40.
    Yavari, Ali
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab). KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Segall, Zary
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab). KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Towards a Semantic-aware Location Positioning for Smart-phones2013Ingår i: 2013 Fifth International Conference on Ubiquitous and Future Networks (ICUFN), IEEE conference proceedings, 2013, s. 487-488Konferensbidrag (Refereegranskat)
    Abstract [en]

    Location-aware services and applications have be- come quite popular in the daily life of mobile users. Global Positioning System (GPS) is available in almost all new smart- phones as a mature and accurate positioning technique. GPS as a satellite-based navigation system, determines the current location of users by receiving signals from satellites. Satellite signals cannot propagate properly inside the buildings, which makes it unusable for indoor positioning. In addition, GPS consumes too much energy to be useful for many applications on mobile phones. There are many proposed alternatives for GPS but they are not as accurate. Combination of those alternatives can improve the accuracy, but varies widely depending on the user behavior and environment. This paper presents a novel architecture for semantic-aware positioning that chooses the best positioning method(s) by exploiting the semantic knowledge. 

  • 41.
    Yavari, Ali
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Martinez Ballesteros, Luis Guillermo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Lungaro, Pietro
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Segall, Zary
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Mobile Service Laboratory (MS Lab).
    Quality of Experience-aware Resource Management for Mobile Video StreamingManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    In this paper, we present a novel experimental approach to quantify the performances of Quality of Experience (QoE)-aware resource management scheme in mobile networks. The main goal of this paper is to improve network efficiency by exploiting in the resource management the knowledge of QoE information associated with online video streaming services. The investigations considered in the paper are performed using an innovative test-bed, developed to assess network efficiency, as well as the impact on the energy consumption at mobile terminal (MT), for the provision of online video services of different qualities. The QoE model used in the proposed QoE-aware allocation scheme assumes a MOS-like grading function whose grades depend on both the duration of playtime interruption and the video quality (resolution). The results show that the proposed resource management scheme can deliver more than 40 percent higher QoE and energy saving at mobile terminal between 12% to 15% to the users of the system as compared to current agnostic (not aware of QoE requirement and content characteristics) service models.

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