A Multi-Channel QoS Model for Random Access Systems

In this paper, we present a simple two-class QoS model for random access systems. We provide a practical mechanism for categorizing the available resources into two distinct service classes prior to medium access. We use an a Markov chain model to define the states and transitions, and derive the system access success probability. This provides a mathematical basis for an accurate model that can be efficiently used to determine the resource allocation for each class. This model provides a useful analytical tool for contention systems that utilize random access for network entry, resource acquisition, and/or contention-based data transmission, e.g. the IEEE 802.16 uplink contention channel. We also study the trade-off between resources allocated and the input traffic from each class. For simplicity, we only consider two classes, however the technique can easily be extended to any number of classes.