Communication costs in digital library databases

  • Bharat Bhargava
  • Melliyal Annamalai
Invited Lecture
Part of the Lecture Notes in Computer Science book series (LNCS, volume 978)


Digital libraries involve various types of data like text, audio, images and video. The data objects are typically very large and of the order of hundreds and thousands of kilobytes. In a digital library, these data objects are distributed in a wide area network. Retrieving large data objects in a wide area network has a high response time. We have conducted experiments to measure the communication overhead in the response time. We have studied the correlation between communication and size of image, between communication and time of day and the communication delay to various sites in a local and wide area network. Images are amenable to losing data without losing semantics of the image. Lossy compression techniques reduce the quality of the image and reduce the size leading to a lower communication delay. We compared the communication delay between compressed and uncompressed images and studied the overhead due to compression and decompression. This enabled us to study the tradeoff between communication time and quality of the image.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    M. Annamalai. An evaluation of transmitting compressed images in a wide area network, MS Thesis, Department of Computer sciences, Purdue University, 1995.Google Scholar
  2. 2.
    B. Bhargava, M. Annamalai, S. Goel, S. Li, E. Pitoura, Y. Zhang, and A. Zhang. DL-Raid: Environment for supporting digital library services. In Lecture Notes in Computer Science Series (LNCS) 916, Digital Libraries, Current Issues, pages 281–300. Springer-Verlag, April 1995.Google Scholar
  3. 3.
    B. Bhargava, S. Li, and J. Huai. Building high performance communication services for digital libraries. In Proceedings of the Forum on Research and Technology Advances in Digital Libraries, McLean, Virginia, May 1995.Google Scholar
  4. 4.
    B. Bhargava, EE. Mafla, J. Riedl, and B. Sauder. Implementation and measurement of efficient communication facilities for distributed database systems. In Proceedings of the Fifth IEEE Data Engineering Conference, Los Angeles, CA. IEEE, 1989.Google Scholar
  5. 5.
    I. H. Witten, A. Moffat, and T. C. Bell. Compression and full-text indexing for digital libraries. In Lecture Notes in Computer Science Series (LNCS) 916, Digital Libraries, Current Issues, pages 181–201. Springer-Verlag, April 1995.Google Scholar
  6. 6.
    A. Zhang, B. Cheng, and R. Acharya. Texture-based image retrieval using fractal codes. Technical Report 95-19, Department of Computer Science, SUNY Buffalo, 1995.Google Scholar
  7. 7.
    X. Zhang, B. Bhargava, H. Zhao, and L. Cheng. Experimental study of tcp and udp protocols for future distributed databases. Technical Report 95-, Department of Computer Science, SUNY Buffalo, 1995.Google Scholar
  8. 8.
    Y. Zhang and B. Bhargava. Wance: A wide area network communication emulation system. In Proceedings of IEEE Workshop on Advances in Parallel and Dis tributed Systems, October 1993.Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1995

Authors and Affiliations

  • Bharat Bhargava
    • 1
  • Melliyal Annamalai
    • 1
  1. 1.Department of Computer SciencesPurdue UniversityW. LafayetteUSA

Personalised recommendations