First step towards an efficient admission control: A complete analytical model for 802.11e EDCA for throughput and delay prediction

Extensive research addressing IEEE 802.11e enhanced distributed channel access (EDCA) performance analysis, by means of analytical models, exist in the literature. It started mainly with the famous Bianchi´s model and still continues today as several aspects have not been covered yet. Unfortunately, the currently proposed models, even though numerous, do not reach the required accuracy due to the great number of simplifications that have been done. Particularly, none of these models considers the 802.11e Contention Free Burst (CFB) mode which allows a given station to transmit a burst of frames without contention during a given Transmission Opportunity Limit (TXOPLimit) time interval. To fill in this gap, we develop in this paper a new and complete analytical model that: (i) reflects the correct functioning of EDCA, (ii) includes all the 802.11e EDCA differentiation parameters, (iii) takes into account all the features of the protocol, and (iv) does not assume saturation conditions. This model is validated by both calculations and simulations.