Packet Routing and Information Gathering in Lines, Rings and Trees

  • Yossi Azar
  • Rafi Zachut
Part of the Lecture Notes in Computer Science book series (LNCS, volume 3669)


We study the problem of online packet routing and information gathering in lines, rings and trees. A network consist of n nodes. At each node a buffer of size B. Each buffer can transmit one packet to the next buffer at each time step. The packets injection is under adversarial control. Packets arriving at a full buffer must be discarded. In information gathering all packets have the same destination. If a packet reaches the destination it is absorbed. The goal is to maximize the number of absorbed packets. Previous studies have shown that even on the line topology this problem is difficult to handle by online algorithms. A lower bound of \({\it \Omega}(\sqrt{n})\) on the competitiveness of the Greedy algorithm was presented by Aiello et al in [1]. All other known algorithms have a near linear competitive ratio. In this paper we give the first O(log n) competitive deterministic algorithm for the information gathering problem in lines, rings and trees. We also consider multi-destination routing where the destination of a packet may be any node. For lines and rings we show an O(log2 n) competitive randomized algorithms. Both for information gathering and for the multi-destination routing our results improve exponentially the previous results.


Greedy Algorithm Competitive Ratio Online Algorithm Information Gathering Discrete Algorithm 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Aiello, W., Ostrovsky, R., Kushilevitz, E., Rosén, A.: Dynamic routing on networks with fixed-size buffers. In: Proc. 14th SODA, pp. 771–780 (2003)Google Scholar
  2. 2.
    Andrews, M., Awerbuch, B., Fernández, A., Kleinberg, J., Leighton, T., Liu, Z.: Universal stability results for greedy contention-resolution protocols. In: Proc. 37th IEEE Symp. on Found. of Comp. Science, pp. 380–389 (1996)Google Scholar
  3. 3.
    Angelov, S., Khanna, S., Kunal, K.: The network as a storage device: Dynamic routing with bounded buffers. In: Chekuri, C., Jansen, K., Rolim, J.D.P., Trevisan, L. (eds.) APPROX 2005 and RANDOM 2005. LNCS, vol. 3624, pp. 1–13. Springer, Heidelberg (2005) (to appear)CrossRefGoogle Scholar
  4. 4.
    Awerbuch, B., Azar, Y., Plotkin, S.: Throughput competitive on-line routing. In: Proc. 34th IEEE Symp. on Found. of Comp. Science, pp. 32–40 (1993)Google Scholar
  5. 5.
    Awerbuch, B., Brinkmann, A., Scheideler, C.: Anycasting and multicasting in adversarial systems: Routing and admission control. In: Proc. 30 ICALP, pp. 1153–1168 (2003)Google Scholar
  6. 6.
    Awerbuch, B., Bartal, Y., Fiat, A., Rosén, A.: Competitive non-preemptive call control. In: Proc. 5’th ACM-SIAM Symp. on Discrete Algorithms, pp. 312–320 (1994)Google Scholar
  7. 7.
    Azar, Y., Richter, Y.: The zero-one principle for switching networks. In: Proc. 36th ACM Symp. on Theory of Computing, pp. 64–71 (2004)Google Scholar
  8. 8.
    Birman, A., Gail, H.R., Hantler, S.L., Rosberg, Z., Sidi, M.: An optimal service policy for buffer systems. Journal of the Association Computing Machinery (JACM) 42(3), 641–657 (1995)MATHMathSciNetGoogle Scholar
  9. 9.
    Borodin, A., Kleinberg, J., Raghavan, P., Sudan, M., Williamson, D.: Adversarial queuing theory. In: Proc. 28th ACM STOC, pp. 376–385 (1996)Google Scholar
  10. 10.
    Kesselman, A., Lotker, Z., Mansour, Y., Patt-Shamir, B.: Buffer overflows of merging streams. In: Di Battista, G., Zwick, U. (eds.) ESA 2003. LNCS, vol. 2832, pp. 349–360. Springer, Heidelberg (2003)CrossRefGoogle Scholar
  11. 11.
    May, M., Bolot, J.C., Jean-Marie, A., Diot, C.: Simple performance models of differentiated services for the internet. In: Proceedings of the IEEE INFOCOM, pp. 1385–1394 (1999)Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2005

Authors and Affiliations

  • Yossi Azar
    • 1
  • Rafi Zachut
    • 1
  1. 1.School of Computer ScienceTel Aviv UniversityTel AvivIsrael

Personalised recommendations