Annales Des Télécommunications

, Volume 54, Issue 11–12, pp 550–564 | Cite as

Vers une nouvelle génération de services de transport adapté aux applications multimédias

Article
  • 27 Downloads

Résumé

Une connexion d’ordre et de fiabilité partiels (POC, partial order connection) est une connexion de transport autorisée à perdre certains objets mais également à les délivrer dans un ordre éventuellement différent de celui d’émission. L’approche POC établit un lien conceptuel entre les protocoles sans connexion au mieux et les protocoles fiables avec connexion. Le concept de POC est motivé par le fait que dans les réseaux hétérogènes sans connexion tels qu’Internet, les paquets transmis sont susceptibles de se perdre et d’arriver en désordre, entraînant alors une réduction des performances des protocoles usuels. De plus, on montre qu’un protocole associé au transport d’un flux multimédia permet une réduction très sensible de l’utilisation des ressources de communication et de mémorisation ainsi qu’une diminution du temps de transit moyen. Dans cet article, une extension temporelle de POC, nommée TPOC (POC temporisé), est introduite. Elle constitue un cadre conceptuel permettant la prise en compte des exigences de qualité de service des applications multimédias réparties. Une architecture offrant un service TPOC est également introduite et évaluée dans le cadre du transport de vidéo MPEG. Il est ainsi démontré que les connexions POC comblent, non seulement le fossé conceptuel entre les protocoles sans connexion et avec connexion, mais aussi qu ’ils surpassent les performances des ces derniers lorsque des données multimédias (telles que la vidéo MPEG) sont transportées.

Mots clés

Protocole communication Couche transport Service multimédia Qualité service Technique description formelle Transmission paquet Signal vidéo Codage image Variation temporelle Architecture système 

Towards a new generation of transport services adapted to multimedia applications

Abstract

A partial order and partial reliable connection (POC) is an end-to-end transport connection authorized to deliver objects in an order that can differ from the transmitted one. The service provided by such a connection is also authorized to lose some objects in a controlled manner. The POC approach establishes a conceptual link between connectionless best-effort (CL) and connection-oriented reliable (co) protocols. POC is motivated by heterogeneous CL networks such as Internet which are plagued by unordered delivery of packets and losses, which in turn tax the performances of current protocols. Moreover, it has been shown, that out of order delivery is able to economize the use of network resources such as memory and bandwidth, and reduces end-to-end transit delay. To take advantage of POC’S benefits, applications must be able to relax some transport constraints. In this paper a temporal extension of POC, called TPOC (for temporal POC), is introduced. TPOC offers a conceptual framework, which allows the Qos of distributed multimedia applications to be taken into account. The architecture for offering a TPOC transport service is introduced and evaluated for the transport of MPEG video streams. We demonstrate that POC connections fill not only the conceptual gap between CL protocols (such as UDP) and CO protocols (such as TCP) but also provides demonstrable performances improvements for the transport of multimedia streams such as MPEG video.

Keywords

Communication protocol Transport layer Multimedia service Quality of service Formal description technique Packet transmission Video signal Picture coding Time variation System architecture 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. [1]
    Amer (P.), Chassot (C), Connolly (T.), Diaz (M.), Conrad (P.). Partial order transport service for multimedia applications,IEEE/ACM Transactions on Networking, 2, n°5, pp. 440–456, (Octobre 1994).CrossRefGoogle Scholar
  2. [2]
    Amer (P.), Chassot (C), Connolly (T.), Diaz (M.). Partial order transport service for multimedia applications : reliable service,2nd International Symposium on High Performance Distributed Computing, Spokane, WA, 21–23, (July 1993).Google Scholar
  3. [3]
    Bestravros (A.), Kim (K.). Exploiting redundancy for timeliness in TCP Boston,Proceedings of RTAS’97: The IEEE Real-time Technology and Applications Symposium, Montreal, Canada, (June 1997).Google Scholar
  4. [4]
    ***Coded representation of picture, audio and multimedia/hypermedia information,CC1TT, Recommendation MPEG-ISO/IEC 111172, Genève, Suisse, (1993).Google Scholar
  5. [5]
    Chaput (E.). Mise en œuvre de la synchronisation dans les systèmes distribués hypermédia,PhD Thesis, Université Paul Sabatier, (December 1998).Google Scholar
  6. [6]
    Chaput (E.), Senac (P.), Diaz (M.), Rojas-Cardenas (L.), Dairaine (L.). Hypermedia synchronization over asynchronous networks,4th International Conference on Multimedia Modeling, Singapore, (November, 1997).Google Scholar
  7. [7]
    Clark (D. D). Tenenhouse (D. L.). Architectural considerations for a new generation of protocols,ACM SIGCOMM, Philadelphia, (September 1990).Google Scholar
  8. [8]
    Courtiat (J. P.), Diaz (M.), Cruz (R.), Sénac (P.). Formal models for the description of time behaviors of multimedia and hypermedia distributed systems,Computer Communications, (1996).Google Scholar
  9. [9]
    Diaz (M.), Lozes (A.), Chassot (C), Amer (P.). Partial order connections: a new concept for high speed and multimedia services and protocols,Annals of Telecommunications, 49, n° 5–6, pp. 270–281, (1994).Google Scholar
  10. [10]
    Eckart (S.), MPEG2play version 1.lb, mpeg Software Simulation Group; ftp.netcom.com:/pub/cfogg/mpeg2, (July 13, 1994).Google Scholar
  11. [11]
    Fournier (M.), Chassot (C), Diaz (M), Lozes (A.). Performance evaluations of partial order connections,7th IFIP Conference on High Performance Networking’97 (HPN’97), New-York, pp. 232–246, (April 1997).Google Scholar
  12. [12]
    Leicher (C). Hierarchical encoding of mpeg sequences using priority encoding transmission (pet),Technical Report TR-94-058, The International Computer Science Institute, Berkeley, (November 1994).Google Scholar
  13. [13]
    Mathis (M.), Mahdavi (J.), Floyd (S.), Romanow (A.). TCP Selective acknowledgment options,IETF RFC 218, (October 1996).Google Scholar
  14. [14]
    Owezarski (P.), Diaz (M.). Models for enforcing multimedia synchronization in visioconférence applications,3rd International conference on Multimedia Modeling, Toulouse, France, (November 1996).Google Scholar
  15. [15]
    Rhee (I.). Error control techniques for interactive low-bit rate video transmission,SIGCOMM, Vancouver, Canada, (1998).Google Scholar
  16. [16]
    Rojas-Cardenas (L.), Dairaine (L.), Senac (P.), Diaz (M.). An adaptive transport service for multimedia streams,IEEE Multimedia Systems, Florence Italy, (Juin 1999).Google Scholar
  17. [17]
    Rojas-Cardenas (L.), Dairaine (L.), Senac (P.), Diaz (M.). Error recovery mechanisms based on retransmissions for video coded with motion compensation techniques,IEEE Packet Video Workshop, New York, U. S. A, (1999).Google Scholar
  18. [18]
    Rojas-Cardenas (L.), Chaput (E.), Dairaine (L.), Senac (P.), Diaz (M.). Video transport over partial order connections,Journal Computer Networks and ISDN System, Elsevier, (April 1999).Google Scholar
  19. [19]
    Rüstche (E.). The architecture of a Gb/s multimedia protocol adapter,ACM SIGCOMM, 23, n° 3, (Jul. 1993).Google Scholar
  20. [20]
    Senac (P.), Diaz (M), de Saqui-Sannes (P.), Leger (A.). Modeling logical and temporal synchronization in Hypermedia systems,IEEE Journal on Selected Areas in Communication, special issue on multimedia synchronization, 14, n° 1, pp. 84–103, (Jan. 1996).Google Scholar
  21. [21]
    Smith (J. M.) and al., Giving Applications Accès to Gb/s Networking,IEEE Network, (July 1993).Google Scholar
  22. [22]
    Turletti (T.), Huitema (C). Videoconferencing on the Internet,IEEE/ACM Transaction on Networking, 4, n° 3, (Jun. 1996).Google Scholar

Copyright information

© Springer-Verlag 1999

Authors and Affiliations

  1. 1.ENSICAToulouse cedexFrance
  2. 2.LAAS-CNRSToulouse cedexFrance

Personalised recommendations