6,355 research outputs found
Self-Optimization of Internet Services with Dynamic Resource Provisioning
Self-optimization through dynamic resource provisioning is an appealing approach to tackle load variation in Internet services. It allows to assign or release resources to/from Internet services according to the varying load. However, dynamic resource provisioning raises several challenges among which: (i) How to plan a good capacity of an Internet service, i.e.~a necessary and sufficient amount of resource to handle the Internet service workload, (ii) How to manage both gradual load variation and load peaks in Internet services, (iii) How to prevent system oscillations in presence of potentially concurrent dynamic resource provisioning, and (iv) How to provide generic self-optimization that applies to different Internet services such as e-mail services, streaming servers or e-commerce web systems. This paper precisely answers these questions. It presents the design principles and implementation details of a self-optimization autonomic manager. It describes the results of an experimental evaluation of the self-optimization manager with a realistic e-commerce multi-tier web application running in a Linux cluster of computers. The experimental results show the usefulness of self-optimization in terms of end-user's perceived performance and system's operational costs, with a negligible overhead
Enhanced adaptive RTCP-based inter-destination multimedia synchronization approach for distributed applications
[EN] Newer social multimedia applications, such as Social TV or networked multi-player games, enable independent groups (or clusters) of users to interact among themselves and share services within the context of simultaneous media content consumption. In such scenarios, concurrently synchronized playout points must be ensured so as not to degrade the user experience on such interaction. We refer to this process as Inter-Destination Multimedia Synchronization (IDMS). This paper presents the design, implementation and evaluation of an evolved version of an RTCP-based IDMS approach, including an Adaptive Media Playout (AMP) scheme that aims to dynamically and smoothly adjust the playout timing of each one of the geographically distributed consumers in a specific cluster if an allowable asynchrony threshold between their playout states is exceeded. For that purpose, we previously had also to develop a full implementation of RTP/RTCP protocols for NS-2, in which we included the IDMS approach as an optional functionality. Simulation results prove the feasibility of such IDMS and AMP proposals, by adopting several dynamic master reference selection policies, to maintain an overall synchronization status (within allowable limits) in each cluster of participants, while minimizing the occurrence of long-term playout discontinuities (such as skips/pauses) which are subjectively more annoying and less tolerable to users than small variations in the media playout rate.This work has been financed, partially, by Universitat Politecnica de Valencia (UPV), under its R&D Support Program in PAID-05-11-002-331 Project and in PAID-01-10. Authors also would like to thank the anonymous reviewers that helped to significantly improve the quality of the paper with their constructive comments.Montagud, M.; Boronat, F. (2012). Enhanced adaptive RTCP-based inter-destination multimedia synchronization approach for distributed applications. Computer Networks. 56(12):2912-2933. https://doi.org/10.1016/j.comnet.2012.05.00329122933561
Coordinated adaptation for adaptive context-aware applications
The ability to adapt to change is critical to both mobile and context-aware applications. This thesis argues that providing sufïŹcient support for adaptive context-aware applications requires support for coordinated adaptation. SpeciïŹcally, the main argument of this thesis is that coordinated adaptation requires applications to delegate adaptation control to an entity that can receive state information from multiple applications and trigger adaptation in multiple applications. Furthermore, coordination requires support for reconïŹguration of the adaptive behaviour and user involvement. Failure to support coordinated adaptation is shown to lead to poor system and application performance and insufïŹcient support for user requirements. An investigation of the existing state-of-the-art in the areas of adaptive and context- aware systems and an analysis of the limitations of existing systems leads to the establishment of a set of design requirements for the support of coordinated adaptation. SpeciïŹcally, adaptation control should be decoupled from the mechanisms implementing the adaptive behaviour of the applications, applications should externalise both state information and the adaptive mechanisms they support and the adaptation control mechanism should allow modiïŹcations without the need for re-implementation of either the application or the support platform. This thesis presents the design of a platform derived from the aforementioned re- quirements. This platform utilises a policy based mechanism for controlling adaptation. Based on the particular requirements of adaptive context-aware applications a new pol- icy language is deïŹned derived from Kowalskyâs Event Calculus logic programming formalism. This policy language allows the speciïŹcation of policy rules where condi- tions are deïŹned through the expression of temporal relationships between events and entities that represent duration (i.e. ïŹuents). A prototype implementation of this design allowed the evaluation of the features offered by this platform. This evaluation reveals that the platform can support coordinated adaptation with acceptable performance cost.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Doctor of Philosophy
dissertationWe propose a collective approach for harnessing the idle resources (cpu, storage, and bandwidth) of nodes (e.g., home desktops) distributed across the Internet. Instead of a purely peer-to-peer (P2P) approach, we organize participating nodes to act collectively using collective managers (CMs). Participating nodes provide idle resources to CMs, which unify these resources to run meaningful distributed services for external clients. We do not assume altruistic users or employ a barter-based incentive model; instead, participating nodes provide resources to CMs for long durations and are compensated in proportion to their contribution. In this dissertation we discuss the challenges faced by collective systems, present a design that addresses these challenges, and study the effect of selfish nodes. We believe that the collective service model is a useful alternative to the dominant pure P2P and centralized work queue models. It provides more effective utilization of idle resources, has a more meaningful economic model, and is better suited for building legal and commercial distributed services. We demonstrate the value of our work by building two distributed services using the collective approach. These services are a collective content distribution service and a collective data backup service
Inter-Destination Multimedia Synchronization; Schemes, Use Cases and Standardization
Traditionally, the media consumption model
has been a passive and isolated activity. However, the
advent of media streaming technologies, interactive social
applications, and synchronous communications, as well as
the convergence between these three developments, point
to an evolution towards dynamic shared media experiences.
In this new model, geographically distributed groups of
consumers, independently of their location and the nature
of their end-devices, can be immersed in a common virtual
networked environment in which they can share multimedia
services, interact and collaborate in real-time within
the context of simultaneous media content consumption. In
most of these multimedia services and applications, apart
from the well-known intra and inter-stream synchronization
techniques that are important inside the consumers
playout devices, also the synchronization of the playout
processes between several distributed receivers, known as
multipoint, group or Inter-destination multimedia synchronization
(IDMS), becomes essential. Due to the
increasing popularity of social networking, this type of
multimedia synchronization has gained in popularity in
recent years. Although Social TV is perhaps the most
prominent use case in which IDMS is useful, in this paper
we present up to 19 use cases for IDMS, each one having
its own synchronization requirements. Different approaches
used in the (recent) past by researchers to achieve
IDMS are described and compared. As further proof of the
significance of IDMS nowadays, relevant organizations
(such as ETSI TISPAN and IETF AVTCORE Group)
efforts on IDMS standardization (in which authors have
been and are participating actively), defining architectures
and protocols, are summarized.This work has been financed, partially, by Universitat Politecnica de Valencia (UPV), under its R&D Support Program in PAID-05-11-002-331 Project and in PAID-01-10, and by TNO, under its Future Internet Use Research & Innovation Program. The authors also want to thank Kevin Gross for providing some of the use cases included in Sect. 1.2.Montagud, M.; Boronat Segui, F.; Stokking, H.; Van Brandenburg, R. (2012). Inter-Destination Multimedia Synchronization; Schemes, Use Cases and Standardization. Multimedia Systems. 18(6):459-482. https://doi.org/10.1007/s00530-012-0278-9S459482186Kernchen, R., Meissner, S., Moessner, K., Cesar, P., Vaishnavi, I., Boussard, M., Hesselman, C.: Intelligent multimedia presentation in ubiquitous multidevice scenarios. IEEE Multimedia 17(2), 52â63 (2010)Vaishnavi, I., Cesar, P., Bulterman, D., Friedrich, O., Gunkel, S., Geerts, D.: From IPTV to synchronous shared experiences challenges in design: distributed media synchronization. Signal Process Image Commun 26(7), 370â377 (2011)Geerts, D., Vaishnavi, I., Mekuria, R., Van Deventer, O., Cesar, P.: Are we in sync?: synchronization requirements for watching on-line video together, CHI â11, New York, USA (2011)Boronat, F., Lloret, J., GarcĂa, M.: Multimedia group and inter-stream synchronization techniques: a comparative study. Inf. Syst. 34(1), 108â131 (2009)Chen, M.: A low-latency lip-synchronized videoconferencing system. In: SIGCHI Conference on Human Factors in Computing Systems, CHIâ03, ACM, pp. 464â471, New York (2003)Ishibashi, Y., Tasaka, S., Ogawa, H.: Media synchronization quality of reactive control schemes. IEICE Trans. Commun. E86-B(10), 3103â3113 (2003)Ademoye, O.A., Ghinea, G.: Synchronization of olfaction-enhanced multimedia. IEEE Trans. Multimedia 11(3), 561â565 (2009)Cesar, P., Bulterman, D.C.A., Jansen, J., Geerts, D., Knoche, H., Seager, W.: Fragment, tag, enrich, and send: enhancing social sharing of video. ACM Trans. Multimedia Comput. Commun. Appl. 5(3), Article 19, 27 pages (2009)Van Deventer, M.O., Stokking, H., Niamut, O.A., Walraven, F.A., Klos, V.B.: Advanced Interactive Television Service Require Synchronization, IWSSIP 2008. Bratislava, June (2008)Premchaiswadi, W., Tungkasthan, A., Jongsawat, N.: Enhancing learning systems by using virtual interactive classrooms and web-based collaborative work. In: Proceedings of the IEEE Education Engineering Conference (EDUCON 2010), pp. 1531â1537. Madrid, Spain (2010)Diot, C., Gautier, L.: A distributed architecture for multiplayer interactive applications on the internet. IEEE Netw 13(4), 6â15 (1999)Mauve, M., Vogel, J., Hilt, V., Effelsberg, W.: Local-lag and timewarp: providing consistency for replicated continuous applications. IEEE Trans. Multimedia 6(1), 45â57 (2004)Hosoya, K., Ishibashi, Y., Sugawara, S., Psannis, K.E.: Group synchronization control considering difference of conversation roles. In: IEEE 13th International Symposium on Consumer Electronics, ISCE â09, pp. 948â952 (2009)Roccetti, M., Ferretti, S., Palazzi, C.: The brave new world of multiplayer online games: synchronization issues with smart solution. In: 11th IEEE Symposium on Object Oriented Real-Time Distributed Computing (ISORC), pp. 587â592 (2008)Ott, D.E., Mayer-Patel, K.: An open architecture for transport-level protocol coordination in distributed multimedia applications. ACM Trans. Multimedia Comput. Commun. Appl. 3(3), 17 (2007)Boronat, F., Montagud, M., Guerri, J.C.: Multimedia group synchronization approach for one-way cluster-to-cluster applications. In: IEEE 34th Conference on Local Computer Networks, LCN 2009, pp. 177â184, ZĂŒrich (2009)Boronat, F., Montagud, M., Vidal, V.: Smooth control of adaptive media playout to acquire IDMS in cluster-based applications. In: IEEE LCN 2011, pp. 617â625, Bonn (2011)Huang, Z., Wu, W., Nahrstedt, K., Rivas, R., Arefin, A.: SyncCast: synchronized dissemination in multi-site interactive 3D tele-immersion. In: Proceedings of MMSys, USA (2011)Kim, S.-J., Kuester, F., Kim, K.: A global timestamp-based approach for enhanced data consistency and fairness in collaborative virtual environments. ACM/Springer Multimedia Syst. J. 10(3), 220â229 (2005)Schooler, E.: Distributed music: a foray into networked performance. In: International Network Music Festival, Santa Monica, CA (1993)Miyashita, Y., Ishibashi, Y., Fukushima, N., Sugawara, S., Psannis K.E.: QoE assessment of group synchronization in networked chorus with voice and video. In: Proceedings of IEEE TENCONâ11, pp. 393â397 (2011)Hesselman, C., Abbadessa, D., Van Der Beek, W., et al.: Sharing enriched multimedia experiences across heterogeneous network infrastructures. IEEE Commun. Mag. 48(6), 54â65 (2010)Montpetit, M., Klym, N., Mirlacher, T.: The future of IPTVâConnected, mobile, personal and social. Multimedia Tools Appl J 53(3), 519â532 (2011)Cesar, P., Bulterman, D.C.A., Jansen, J.: Leveraging the user impact: an architecture for secondary screens usage in an interactive television environment. ACM/Springer Multimedia Syst. 15(3), 127â142 (2009)Lukosch, S.: Transparent latecomer support for synchronous groupware. In: Proceedings of 9th International Workshop on Groupware (CRIWG), Grenoble, France, pp. 26â41 (2003)Steinmetz, R.: Human perception of jitter and media synchronization. IEEE J. Sel. Areas Commun. 14(1), 61â72 (1996)Stokking, H., Van Deventer, M.O., Niamut, O.A., Walraven, F.A., Mekuria, R.N.: IPTV inter-destination synchronization: a network-based approach, ICINâ2010, Berlin (2010)Mekuria, R.N.: Inter-destination media synchronization for TV broadcasts, Master Thesis, Faculty of Electrical Engineering, Mathematics and Computer Science, Department of Network architecture and Services, Delft University of Technology (2011)Pitt Ian, CS2511: Usability engineering lecture notes, localisation of sound sources. http://web.archive.org/web/20100410235208/http:/www.cs.ucc.ie/~ianp/CS2511/HAP.htmlNielsen, J.: Response times: the three important limits. http://www.useit.com/papers/responsetime.html (1994)ITU-T Rec G. 1010: End-User Multimedia QoS Categories. International Telecommunication Union, Geneva (2001)Biersack, E., Geyer, W.: Synchronized delivery and playout of distributed stored multimedia streams. ACM/Springer Multimedia Syst 7(1), 70â90 (1999)Xie, Y., Liu, C., Lee, M.J., Saadawi, T.N.: Adaptive multimedia synchronization in a teleconference system. ACM/Springer Multimedia Syst. 7(4), 326â337 (1999)Laoutaris, N., Stavrakakis, I.: Intrastream synchronization for continuous media streams: a survey of playout schedulers. IEEE Netw. Mag. 16(3), 30â40 (2002)Ishibashi, Y., Tsuji, A., Tasaka, S.: A group synchronization mechanism for stored media in multicast communications. In: Proceedings of the INFOCOM â97, Washington (1997)Ishibashi, Y., Tasaka, S.: A group synchronization mechanism for live media in multicast communications. IEEE GLOBECOMâ97, pp. 746â752 (1997)Boronat, F., Guerri, J.C., Lloret, J.: An RTP/RTCP based approach for multimedia group and inter-stream synchronization. Multimedia Tools Appl. J. 40(2), 285â319 (2008)Ishibashi, I., Tasaka, S.: A distributed control scheme for group synchronization in multicast communications. In: Proceedings of International Symposium Communications, Kaohsiung, Taiwan, pp. 317â323 (1999)Lu, Y., Fallica, B., Kuipers, F.A., Kooij, R.E., Van Mieghem, P.: Assessing the quality of experience of SopCast. Int. J. Internet Protoc. Technol 4(1), 11â19 (2009)Shamma, D.A., Bastea-Forte, M., Joubert, N., Liu, Y.: Enhancing online personal connections through synchronized sharing of online video, ACM CHIâ08 Extended Abstracts, Florence (2008)Ishibashi, Y., Tasaka, S.: A distributed control scheme for causality and media synchronization in networked multimedia games. In: Proceedings of 11th International Conference on Computer Communications and Networks, pp. 144â149, Miami, USA (2002)Ishibashi, Y., Tomaru, K., Tasaka, S., Inazumi, K.: Group synchronization in networked virtual environments. In: Proceedings of the 38th IEEE International Conference on Communications, pp. 885â890, Alaska, USA (2003)Tasaka, S., Ishibashi, Y., Hayashi, M.: Interâdestination synchronization quality in an integrated wired and wireless network with handover. IEEE GLOBECOM 2, 1560â1565 (2002)Kurokawa, Y., Ishibashi, Y., Asano, T.: Group synchronization control in a remote haptic drawing system. In: Proceedings of IEEE International Conference on Multimedia and Expo, pp. 572â575, Beijing, China (2007)Hashimoto, T., Ishibashi, Y.: Group Synchronization Control over Haptic Media in a Networked Real-Time Game with Collaborative Work, Netgamesâ06, Singapore (2006)Nunome, T., Tasaka, S.: Inter-destination synchronization quality in a multicast mobile ad hoc network. In: Proceedings of IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications, pp. 1366â1370, Berlin, Germany (2005)Brandenburg, R., van Stokking, H., Van Deventer, M.O., Boronat, F., Montagud, M., Gross, K.: RTCP for inter-destination media synchronization, draft-brandenburg-avtcore-rtcp-for-idms-03.txt. In: IETF Audio/Video Transport Core Maintenance Working Group, Internet Draft, March 9 (2012)ETSI TS 181 016 V3.3.1 (2009-07) Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN); Service Layer Requirements to integrate NGN Services and IPTVETSI TS 182 027 V3.5.1 (2011-03) Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN); IPTV Architecture; IPTV functions supported by the IMS subsystemETSI TS 183 063 V3.5.2 (2011-03) Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN); IMS-based IPTV stage 3 specificationBrandenburg van, R., et al.: RTCP XR Block Type for inter-destination media synchronization, draft-brandenburg-avt-rtcp-for-idms-00.txt. In: IETF Audio/Video Transport Working Group, Internet Draft, Sept 24, 2010Williams, A., et al.: RTP Clock Source Signalling, draft-williams-avtcore-clksrc-00. In: IETF Audio/Video Transport Working Group, Internet Draft, February 28, 201
Smart PIN: performance and cost-oriented context-aware personal information network
The next generation of networks will involve interconnection of heterogeneous individual
networks such as WPAN, WLAN, WMAN and Cellular network, adopting the IP as common infrastructural protocol and providing virtually always-connected network. Furthermore,
there are many devices which enable easy acquisition and storage of information as pictures, movies, emails, etc. Therefore, the information overload and divergent contentâs
characteristics make it difficult for users to handle their data in manual way. Consequently, there is a need for personalised automatic services which would enable data exchange across heterogeneous network and devices. To support these personalised services, user centric approaches
for data delivery across the heterogeneous network are also required.
In this context, this thesis proposes Smart PIN - a novel performance and cost-oriented context-aware Personal Information Network. Smart PIN's architecture is detailed including its network, service and management components. Within the service component, two novel schemes for efficient delivery of context and content data are proposed:
Multimedia Data Replication Scheme (MDRS) and Quality-oriented Algorithm for Multiple-source Multimedia Delivery (QAMMD).
MDRS supports efficient data accessibility among distributed devices using data replication which is based on a utility function and a minimum data set. QAMMD employs a buffer underflow avoidance scheme for streaming, which achieves high multimedia quality without content adaptation to network conditions. Simulation models for MDRS and
QAMMD were built which are based on various heterogeneous network scenarios. Additionally a multiple-source streaming based on QAMMS was implemented as a prototype and tested in an emulated network environment. Comparative tests show that MDRS and QAMMD perform significantly better than other approaches
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