| 1. |
- Debernardi, Nicolas, et al.
(författare)
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Services Provisioning and Terminal Cooperation in User-Deployed Networks
- 2006
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Ingår i: IEEE International Symposium on Personal, Indoor, and Mobile Radio Communications workshops. - 2166-9570 .- 2166-9589.
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 2. |
- Devlic, Alisa, et al.
(författare)
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Energy consumption reduction via context-aware mobile video pre-fetching
- 2012
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Ingår i: Proceedings - 2012 IEEE International Symposium on Multimedia, ISM 2012. - : IEEE. - 9780769548753 ; , s. 261-265
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Konferensbidrag (refereegranskat)abstract
- 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.
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| 3. |
- Devlic, Alisa, et al.
(författare)
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Evaluation of energy profiles for mobile video prefetching in generalized stochastic access channels
- 2014
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Ingår i: Mobile and Ubiquitous Systems: Computing, Networking, and Services. - Cham : Springer. - 9783319115689 ; , s. 209-223
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Konferensbidrag (refereegranskat)abstract
- 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.
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| 4. |
- Devlic, Alisa, et al.
(författare)
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QoE-aware optimization for video delivery and storage
- 2015
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Ingår i: 2015 IEEE 16th International Symposium on "A World of Wireless, Mobile and Multimedia Networks" (WoWMoM) 2015. - Boston, MA, USA. - 9781479984619 ; , s. 1-10
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Konferensbidrag (refereegranskat)abstract
- 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.
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| 5. |
- Devlic, Alisa, et al.
(författare)
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Towards QoE-aware adaptive video streaming
- 2016
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Ingår i: 2015 IEEE 23rd International Symposium on Quality of Service (IWQoS). - : IEEE. - 9781467371131 ; , s. 75-76
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Konferensbidrag (refereegranskat)abstract
- 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.
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| 6. |
- Hultell, Johan, et al.
(författare)
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Service Provisioning with Ad-Hoc Deployed High-Speed Access Points in Urban environments
- 2005
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Ingår i: 2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2005. - : IEEE conference proceedings. - 9783800729098 ; , s. 2019-2023
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Konferensbidrag (refereegranskat)abstract
- 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.
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| 7. |
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| 8. |
- Kamaraju, Pavan, et al.
(författare)
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A novel paradigm for context-aware content pre-fetching in mobile networks
- 2013
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Ingår i: 2013 IEEE Wireless Communications and Networking Conference (WCNC). - : IEEE Communications Society. - 9781467359399 ; , s. 4534-4539
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Konferensbidrag (refereegranskat)abstract
- 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.
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| 9. |
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| 10. |
- Lindström, Magnus, et al.
(författare)
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Forwarding Incentives by Means of Resource Delegation and Rewards in Multihop Cellular Networks
- 2005
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Ingår i: RVK05 - Radiovetenskap och kommunikation.
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Konferensbidrag (refereegranskat)abstract
- 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.
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