Modeling frame-level errors in GSM wireless channels

We compare four different approaches to modeling frame-level errors in GSM channels. One of these, the Markov-based Trace Analysis (MTA) model, was developed explicitly for this purpose. The next two, kth-order Markov models and hidden Markov models (HMMs), have been widely used to model loss in wired networks. All three of these have difficulty in modeling empirical GSM frame-level error traces. The MTA model and HMM predict frame-error rates substantially different from that measured from the trace, and all three models have difficulty in capturing the long term temporal correlation structure. We propose a fourth model, the extended On/Off model, which alternates between an On (error-free) and an Off (error-filled) state. The state holding times are taken from mixtures of geometric distributions. We show that this model, with mixtures of 4–7 geometric distributions captures first- and second-order statistics significantly better than the preceding three approaches.