Stability boundaries between non-saturation and saturation regimes for IEEE 802.11e EDCA

In this paper we investigate the transition between non-saturation and saturation regimes for the EDCA function within the IEEE 802.11e standard. We develop queueing and Markov chain models for node operation, and demonstrate interaction among traffic classes in transition from non-saturation to saturation regime. We derive probability generating functions (PGFs) for the probability distributions of packet service time and buffer occupancy. We also derive Laplace-Stieltjes transform (LST) for the probability distribution of frame response time and show stability limits for each traffic class.