Real-time voice communication over the internet using packet path diversity

ABSTRACT

The quality of real-time voice communication over best-effort networks is mainly determined by the delay and loss characteristics observed along the network path. Excessive playout buffering at the receiver is prohibitive and significantly delayed packets have to be discarded and considered as late loss. We propose to improve the tradeoff among delay, late loss rate, and speech quality using multi-stream transmission of real-time voice over the Internet, where multiple redundant descriptions of the voice stream are sent over independent network paths. Scheduling the playout of the received voice packets is based on a novel multi-stream adaptive playout scheduling technique that uses a Lagrangian cost function to trade delay versus loss. Experiments over the Internet suggest largely uncorrelated packet erasure and delay jitter characteristics for different network paths which leads to a noticeable path diversity gain. We observe significant reductions in mean end-to-end latency and loss rates as well as improved speech quality when compared to FEC protected single-path transmission at the same data rate. In addition to our Internet measurements, we analyze the performance of the proposed multi-path voice communication scheme using the ns network simulator for different network topologies, including shared network links.

REFERENCES

• 1: David Andersen , Hari Balakrishnan , Frans Kaashoek , Robert Morris, Resilient overlay networks, Proceedings of the eighteenth ACM symposium on Operating systems principles, October 21-24, 2001, Banff, Alberta, Canada
• 2: J. G. Apostolopoulos. Reliable video communication over lossy packet networks using multiple state encoding and path diversity. In Proceedings Visual Communication and Image Processing, pages 392-409, Jan. 2001.
• 3: M. Arlitt and T. Jin. Workload characterization study of the 1998 World Cup web site. IEEE Network, 14(3):30-7, May 2000.
• 4: Jean-Chrysotome Bolot, End-to-end packet delay and loss behavior in the internet, ACM SIGCOMM Computer Communication Review, v.23 n.4, p.289-298, Oct. 1993
• 5: J.-C. Bolot, S. Fosse-Parisis, and D. Towsley. Adaptive FEC-based error control for Internet telephony. In Proceedings of IEEE INFOCOM '99, volume 3, pages 1453-1460, Mar. 1999.
• 6: V. Hardman, A. Sasse, and A. Watson. Reliable audio for use over the Internet. In Proceedings of INET '95, pages 171-178, Jurle 1995.
• 7: R. V. Hogg and E. A. Tanis. Probability and statistical inference. Macmillan Pulishing Company, 4th edition, 1993.
• 8: ITU-T Recommendation G.726. 40, 32, 24, 16 kbit/s Adaptive differential pulse code modu.lation (ADPCM), Dec. 1990.
• 9: ITU-T Recommendation P.862. Perceptual evaluation of speech quality (PESQ), an objective ,meth,od for e,n.d-to-en,d speech quality assessmerct of narro,w-band telephone networks and speech codecs, Feb. 2001.
• 10: W. Jiang and A. Ortega. Multiple description speech coding for robust communication over lossy packet networks. In Internationul Conference o'n Multimedia a,nd Ezpo, volume 1, pages 44447, Aug. 2000. New York, NY, USA.
• 11: G . K b. u m and W. Kleijn. Multiple-description coding (MDC) of speech with an invertible auditory model. In 1999 IEEE Workshop on Speech Coding Proceedings, pages 81 -3, June 1999. Porvoo, Finland.
• 12: Y. J. Liang, N. Farber, and B. Girod. Adaptive playout scheduling and loss concealment for voice communication over IP networks. Submitted to IEEE Trunsactions o Multimedia, Feb. 2001. Online at: http://www-ise.stanford.edu/-yiliang/publications/
• 13: Y. J. Liang, N. Farber, and B. Girod. Adaptive playout scheduling using time-scale modification in packet voice communications. In 2001 IEEE International Conference on Acoustics, Speech, und Signal Processing. Proceedings ICASSPOI, May 2001. Salt Lake City, UT.
• 14: Y. J. Liang, E. G. Steinbach, and B. Girod. Multi-stream voice over IP using packet path diversity. In Proceedings of IEEE 4th Workshop on Multimediu Signal Processing, Oct. 2001.
• 15: D. Mills. Internet Time Synchronization the Network Time Protocol. RFC-1129, Internet Engineering Task Force, Oct. 1989.
• 16: H. Sanneck and N. T. L. Le. Speech property-based FEC for Internet telephony applications. In Proceedings of SPIE - The International Society for Optical Engineering, volume 3969, pages 38-51, Jan. 2000.
• 17: Stefan Savage , Andy Collins , Eric Hoffman , John Snell , Thomas Anderson, The end-to-end effects of Internet path selection, ACM SIGCOMM Computer Communication Review, v.29 n.4, p.289-299, Oct. 1999
• 18: R. Singh and A. Ortega. Erasure recovery in predictive coding environments using multiple description coding. In 1999 IEEE Third Workshop on Multimedia Signal Processing, pages 33338, Sept. 1999. Copenhagen, Denmark.
• 19: B. Wah and D. Lin. Transformation-based reconstruction for real-time voice transmissions over the Internet. IEEE Tmnsactions on Multimedia, 1(4):3422351, Dec. 1999.

INDEX TERMS

Primary Classification:
  C. Computer Systems Organization
  C.3 SPECIAL-PURPOSE AND APPLICATION-BASED SYSTEMS
      Subjects: Real-time and embedded systems

Additional Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS
      C.2.1 Network Architecture and Design
          Subjects: Packet-switching networks

  H. Information Systems
  H.4 INFORMATION SYSTEMS APPLICATIONS
      H.4.3 Communications Applications

          Nouns: Internet

General Terms:
Design, Measurement, Performance

Keywords:
adaptive playout scheduling, forward error correction, multi-path, multi-stream transmission, multiple description coding, packet path diversity, transmission, voice over IP