The Data Broadcast Problem with Preemption
The data-broadcast problem consists in finding an infinite schedule to broadcast a given set of messages so as to minimize the average response time to clients requesting messages, and the cost of the broadcast. This is an efficient means of disseminating data to clients, designed for environments, such as satellites, cable TV, mobile phones, where there is a much larger capacity from the information source to the clients than in the reverse direction.
Previous work concentrated on scheduling indivisible messages. Here, we studied a generalization of the model where the messages can be preempted. We show that this problem is NP-hard, even in the simple setting where the broadcast costs are zero, and give some practical 2-approximation algorithms for broadcasting messages. We also show that preemption can improve the quality of the broadcast by an arbitrary factor.
Unable to display preview. Download preview PDF.
- Acharya, S.Broadcast Disks: Dissemination-based Management for Assymmetric Communication Environments. PhD thesis, Brown University, 1998.Google Scholar
- Anily, S., Glass, C. A., and Hassin, R. The scheduling of maintenance service. To appear (http://www.math.tau.ac.il/~hassin).
- Bar-Noy, A., Bhatia, R., Naor, J. S., and Schieber, B. Minimizing service and operation costs of periodic scheduling. In Proc. of the 9th Annual ACM-SIAM Symp. on Discrete Algorithms (SODA) (1998), pp. 11–20.Google Scholar
- Bar-Noy, A., and Shilo, Y. Optimal broadcasting of two files over an asymmetric channel. In Proc. of Infocom (1999).Google Scholar
- Gecsei, J. The architecture of videotex systems. Prentice Hall, Englewood Cliffs, N.J. (1983).Google Scholar
- Imielinski, T., Viswanathan, S., and Badrinath, B. Energy efficient indexing on air. In SIGMOD (May 1994).Google Scholar
- Kenyon, C., and Schabanel, N. The data broadcast problem with non-uniform transimission times. In Proc. of the 10th SODA (1999), pp. 547–556.Google Scholar
- Kenyon, C., Schabanel, N., and Young, N. E. Polynomial time approximation scheme for data broadcast. Submitted, Oct 1999.Google Scholar
- Khanna, S., and LIBERATORE, V. On broadcast disk paging. In Proceedings of 30th STOC (1998), vol. 30, pp. 634–643.Google Scholar
- Khanna, S., and Zhou, S. On indexed data broadcast. In Proceedings of 30th STOC (1998), vol. 30, pp. 463–472.Google Scholar
- Shekhar, S., and Liu, D. Genesis: An approach to data dissemination in Advanced Traveller Information Systems (ATIS). In IEEE Data Engineering Bulletin (Sept. 1996), vol. 19(3).Google Scholar
- Tan, K., and Xu, J. Energy efficient filtering of nonuniform broadcast. In Proc. of the 16thInt. Conf. in Distributed Computing System (1996), pp. 520–527.Google Scholar
- Vaidya, N., and Hameed, S. Log time algorithms for scheduling single and multiple channel data broadcast. In Proc. of the 3rd ACM/IEEE Conf. on Mobile Computing and Networking (MOBICOM) (Sep. 1997).Google Scholar
- Vishwanath, S.Publishing in wireless and wireline environments. PhD thesis, Rutgers University, 1994.Google Scholar