| 1. |
- Briat, Corentin, et al.
(författare)
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A conservation-law-based modular fluid-flow model for network congestion modeling
- 2012
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Ingår i: 2012 Proceedings - IEEE INFOCOM. - : IEEE Computer Society. - 9781467307758 ; , s. 2050-2058
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Konferensbidrag (refereegranskat)abstract
- A modular fluid-flow model for network congestion analysis and control is proposed. The model is derived from an information conservation law stating that the information is either in transit, lost or received. Mathematical models of network elements such as queues, users, and transmission channels, and network description variables, including sending/ acknowledgement rates and delays, are inferred from this law and obtained by applying this principle locally. The modularity of the devised model makes it sufficiently generic to describe any network topology, and appealing for building simulators. Previous models in the literature are often not capable of capturing the transient behavior of the network precisely, making the resulting analysis inaccurate in practice. Those models can be recovered from exact reduction or approximation of this new model. An important aspect of this particular modeling approach is the introduction of new tight building blocks that implement mechanisms ignored by the existing ones, notably at the queue and user levels. Comparisons with packet-level simulations corroborate the proposed model.
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| 2. |
- Briat, Corentin, et al.
(författare)
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Impact of Queueing Delay Estimation Error on Equilibrium and Its Stability
- 2011
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Ingår i: NETWORKING 2011, PT II. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 9783642207983 ; , s. 356-367
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Konferensbidrag (refereegranskat)abstract
- Delay-based transmission control protocols need to separate round-trip time (RTT) measurements into their constituting parts: the propagation and the queueing delays. We consider two means for this; the first is to take the propagation delay as the minimum observed RTT value, and the second is to measure the queueing delay at the routers and feed it back to the sources. We choose FAST-TCP as a representative delay-based transmission control protocol for analysis and study the impact of delay knowledge errors on its performance. We have shown that while the first method destroys fairness and the uniqueness of the equilibrium, the stability of the protocol can easily be obtained through tuning the protocol terms appropriately. Even though the second technique is shown to preserve fairness and uniqueness of the equilibrium point, we have presented that unavoidable oscillations can occur around the equilibrium point.
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| 3. |
- Chen, Zhaofei, et al.
(författare)
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Demo of a collaborative music sharing system
- 2012
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Ingår i: MobiOpp'12 - Proceedings of the 3rd ACM International Workshop on Mobile Opportunistic Networks. - New york : ACM. - 9781450312080 ; , s. 77-78
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Konferensbidrag (refereegranskat)abstract
- We demonstrate a wireless real-time music-sharing application that lets users play music directly from their mobiles through a jukebox. We have designed and implemented the application by using a previously developed content-centric opportunistic networking middleware. The jukebox plays the music file that is first in its playlist by streaming it in real-time from the publishing user device. All users can observe the collaboratively formed playlist on their mobiles in real-time. The application shows the usefulness of our middleware and demonstrates a new form of situated applications. The application handles churn and garbage collection after departed users.
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| 4. |
- Fortetsanakis, G., et al.
(författare)
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To subscribe, or not to subscribe : Modeling and analysis of service paradigms in cellular markets
- 2012
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Ingår i: 2012 IEEE International Symposium on Dynamic Spectrum Access Networks, DYSPAN 2012. - : IEEE. - 9781467344487 ; , s. 189-200
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Konferensbidrag (refereegranskat)abstract
- Traditionally customers subscribe to specific providers and are served by accessing base stations (BSs) of the network of their provider. Inevitably subscribers with relatively 'high' usage pattern and data-rate requirements are subsidized by the ones with lower usage and data-rates. As the wireless technology advances, a diverse set of services will be available. This paper introduces the 'flex service' paradigm that allows a customer to dynamically access BSs of different providers based on various criteria, such as profile, network conditions, and offered prices. 'Flex users' can select the appropriate provider and BS on a per-session basis. This work considers a diverse customer population with respect to their demand, their preference on data-rate over price, their tolerance on the blocking probabilities of their sessions, and their willingness to pay for certain services. Users can dynamically decide to buy a long-term subscription or become flex users. In this paper, we develop a rich framework for modeling and analysis of such markets in different spatio-temporal scales. We analyze the evolution of markets with the flex service paradigm, focusing on whether it can improve the quality-of-service (QoS), social welfare, flexibility and further enhance the competition among providers. The main contribution of this paper is detailed modeling and indepth performance analysis of such complex markets, in different spatial and temporal scales. It considers the perspective of clients, providers, and regulators. It demonstrates the benefits of markets with the flex service paradigm and compares them with the ones that only offer subscription contracts.
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| 5. |
- Helgason, Ólafur, et al.
(författare)
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A Middleware for Opportunistic Content Distribution
- 2016
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Ingår i: Computer Networks. - : Elsevier. - 1389-1286 .- 1872-7069. ; 107, s. 178-193
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Tidskriftsartikel (refereegranskat)abstract
- In this work we present a middleware architecture for a mobile peer-to-peer content distribution system. Our architecture allows wireless content dissemination between mobile nodes without relying on infrastructure support. In addition, it supports the dissemination of contents between the wireless ad-hoc domain and the wired Internet. In the ad-hoc domain, contents are exchanged opportunistically when nodes are within communication range. Applications access the service of our platform through a publish/subscribe interface and therefore do not have to deal with low-level opportunistic networking issues or matching and soliciting of contents. Our middleware consists of three key components. A content structure that facilitates dividing contents into logical topics and allows efficient matching of content lookups and downloading under sporadic node connectivity. A solicitation protocol that allows nodes to solicit content meta-information in order to discover contents available at a neighboring node and to download content entries disjointedly from different nodes. An API that allows applications to access the system services through a publish/subscribe interface. In this work we present the design and implementation of our middleware and describe a set of applications that use the services provided by our middleware. We also assess the performance of the system using our Android implementation as well as a simulation implementation for large-scale evaluation.
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| 6. |
- Helgason, Ólafur, et al.
(författare)
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A mobile peer-to-peer system for opportunistic content-centric networking
- 2010
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Ingår i: Proceedings of the 2nd ACM SIGCOMM Workshop on Networking, Systems, and Applications on Mobile Handhelds, MobiHeld '10, Co-located with SIGCOMM 2010. - New York, NY, USA : ACM. - 9781450301978 ; , s. 21-26
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Konferensbidrag (refereegranskat)abstract
- In this work we present a middleware architecture for a mobile peer-to-peer content distribution system. Our architecture allows wireless content dissemination between mobile nodes without relying on infrastructure support. Contents are exchanged opportunistically when nodes are within communication range. Applications access the service of our platform through a publish/subscribe interface and therefore do not have to deal with low-level opportunistic networking issues or matching and soliciting of contents. Our architecture consists of three key components. A content structure that facilitates dividing contents into logical topics and allows for efficient matching of content lookups and downloading under sporadic node connectivity. A solicitation protocol that allows nodes to solicit content meta-information in order to discover contents available at a neighboring node and to download content entries disjointedly from different nodes. An API that allows applications to access the system services through a publish/subscribe interface. In this work we describe the design and implementation of our architecture. We also discuss potential applications and present evaluation results from profiling of our system.
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| 7. |
- Karlsson, Gunnar, et al.
(författare)
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A Future Wireless Internet Beyond Generations
- 2010
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Ingår i: Proceedings of the 5th International Conference on Future Internet Technologies, CFI10. - New York, NY, USA : ACM. - 9781450302302 ; , s. 5-9
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Konferensbidrag (refereegranskat)abstract
- The use of licensed spectrum for wireless communication is driven by the need to control interference between operators. This regulation leads to inefficient utilization of spectrum and causes shortage of free spectrum that hinders the entry of new operators and introduction of new wireless technologies. In this work, we present an evolutionary model for which license-free operation is the spectrum sharing mode so that networks can be built freely by anyone and new technologies can be deployed as soon as they become available. The paradigm assumes users to have open access to all public networks without prior contracts with operators. Hence, freely roaming users will drive competition among wireless network access providers, who in turn can meet demand quickly by offering access at low price, high quality, in hitherto uncovered areas, and by means of novel superior technology. We present a straw-man design and discuss the inherent technical challenges that must be addressed.
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| 8. |
- Kouyoumdjieva, Sylvia, et al.
(författare)
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Evaluating an Energy-efficient Radio Architecture for Opportunistic Communication
- 2012
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Ingår i: Communications (ICC), 2012 IEEE International Conference on. - : IEEE. - 9781457720529 ; , s. 5751-5756
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Konferensbidrag (refereegranskat)abstract
- A major challenge for wireless networks is to minimize the energy consumption in the mobile devices. This work evaluates potential performance gains of a dual-radio architecture in which a low power radio is used to wake up the primary high power radio. Our targeted domain is opportunistic communication directly between devices. We show that it can significantly reduce the energy consumption at a price of slightly decreased goodput. We also examine the effect of the MAC protocol on the performance of the dual-radio system and we point out that in dense scenarios MAC layer protocols, such as of 802.15.4, do not perform well. We observe that information on device density of an environment can be used to address this shortcoming.
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| 9. |
- Kouyoumdjieva, Sylvia, et al.
(författare)
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Opportunistic Content-Centric Networking : The Conference Case Demo
- 2011
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Ingår i: Proceedings of the IEEE International Conference on Computer Communications, INFOCOM’11.
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Konferensbidrag (refereegranskat)abstract
- We present a demonstration scenario to evaluate a middleware architecture that we designed and implemented for distributing content over mobile ad hoc networks. The peer to-peer networking architecture allows content dissemination between mobile devices without relying on any infrastructure support. Content is exchanged opportunistically when nodes are in proximity. We developed a mobile application utilizing the services provided by the implemented middleware. The application facilitates opportunistic content distribution in both one-to-one and one-to-many dissemination modes.
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| 10. |
- Pajevic, Ljubica, et al.
(författare)
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Demo : Opportunistic Mobile Social Networking
- 2011
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Ingår i: Proc. ACM Annual International Conference on Mobile Systems, Applications and Services, MobiSys’11. - New York, NY, USA : ACM.
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Konferensbidrag (refereegranskat)abstract
- We present a demonstration scenario to validate a middleware architecture that we designed and implemented for distributing content between mobile users in an opportunistic manner. The peer-to-peer networking architecture allows content dissemination between mobile devices without relying on any infrastructure support. We developed a mobile application utilizing the services provided by the implemented middleware. The application facilitates opportunistic content distribution in both one-to-one and one-to-many dissemination modes.
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