Probabilistic QoS Guarantees with FP/EDF Scheduling and Packet Discard in a Real Time Context: A Comparative Study of Local Deadline Assignment Techniques

  • Fadhel Karim Maïna
  • Leila Azouz Saïdane
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4268)


In this paper, we are interested in comparing local deadline assignment techniques in a multi-hop network supporting real time traffic with end-to-end delay constraints, when the FP/EDF scheduling is used, assuming that packets which don’t respect their local delay constraints are discarded. In each node, packets are scheduled according to their Fixed Priorities (FP), and within the same priority, packets are scheduled according to the Earliest Deadline First (EDF) policy, using local deadlines, which correspond to the sojourn times not to be exceeded in that node. Consequently, an accurate choice of these local deadlines must be done in order to respect the flows’ end-to-end delay constraints and minimize the packet discard rate. As we are interested in giving probabilistic QoS guarantees, we develop a mathematical model to compare the performances of five existing deadline assignment techniques. We show that all these techniques give very high packet discard rates. So, we propose to use another packet discard policy and we show that it gives better results.


Sojourn Time Laplace Transform Delay Constraint Earliest Deadline First Expedite Forwarding 
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.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2006

Authors and Affiliations

  • Fadhel Karim Maïna
    • 1
  • Leila Azouz Saïdane
    • 1
  1. 1.Ensi, laboratoire CristalUniversity of ManoubaTunisia

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