A Markov-Based Channel Model Algorithm for Wireless Networks
Ben Y. Zhao
Anthony D. Joseph
Journal on Wireless Networks
May 2003, Vol. 9, No. 3, Pgs. 189-199.
Published by the ACM and Baltzer Publishers
[Full Text in PDF Format, 321KB]
Techniques for modeling and simulating channel conditions play an essential
role in understanding network protocol and application behavior. In previous
work, we demonstrated that inaccurate modeling using a traditional analytical
model yielded significant errors in error control protocol parameters choices.
In this paper, we demonstrate that time-varying effects on wireless channels
result in wireless traces which exhibit non-stationary behavior over small
window sizes. We then present an algorithm that divides traces into stationary
components in order to provide analytical channel models that, relative
to traditional approaches, more accurately represent characteristics such
as burstiness, statistical distribution of errors, and packet loss processes.
Our algorithm also generates artificial traces with the same statistical
characteristics as actual collected network traces. For validation, we
develop a channel model for the circuit-switched data service in GSM and
show that it: (1) more closely approximates GSM channel characteristics
than traditional Markov models and (2) generates artificial traces that
closely match collected traces' statistics. Using these traces in a simulator
environment enables future protocol and application testing under different
controlled and repeatable conditions.