Multiscale Queuing Analysis of Long-Range-Dependent Network Traffic
Vinay Ribeiro (vinay@rice.edu)
Electrical and Computer Engineering, Rice University
Rudolf Riedi (riedi@rice.edu)
Electrical and Computer Engineering, Rice University
Matthew Crouse (mcrouse@ece.rice.edu)
Electrical and Computer Engineering, Rice University
Richard Baraniuk (richb@rice.edu)
Electrical and Computer Engineering, Rice University
Many studies have indicated the importance of capturing
scaling properties when modeling traffic loads; however, the influence of
long-range dependence (LRD) and marginal statistics still remains on
unsure footing. In this paper, we study these two issues by
introducing a multiscale traffic model and a novel multiscale
approach to queuing analysis. The multifractal wavelet model (MWM)
is a multiplicative, wavelet-based model that captures the
positivity, LRD, and ``spikiness'' of non-Gaussian traffic. Using a
binary tree, the model synthesizes an N-point data set with only
O(N) computations.
Leveraging the tree structure of the model, we
derive a multiscale queuing analysis that provides a simple closed
form approximation to the tail queue probability, valid for any
given buffer size. The analysis is applicable not only to the MWM
but to tree-based models in general, including fractional Gaussian
noise. Simulated queuing experiments demonstrate the accuracy of
the MWM for matching real data traces and the precision of our
theoretical queuing formula. Thus, the MWM is useful not only for
fast synthesis of data for simulation purposes but also for
applications requiring accurate queuing formulas such as call admission
control. Our results clearly indicate that the marginal
distribution of traffic at different time-resolutions affects
queuing and that a Gaussian assumption can lead to over-optimistic
predictions of tail queue probability even when taking LRD into
account.