A simple but accurate throughput model for IEEE 802.11 EDCA in saturation and non-saturation conditions
Mathematical modeling and performance analysis of the IEEE 802.11e Enhanced Distributed Channel Access (EDCA) has been the subject of several research papers published in the literature. However, the Packet Fragmentation (PF) which has been proposed by the IEEE work group in the legacy IEEE 802.11 standard, has never been taken into account in the mathematical models available in the literature, in order to analyze the performance of the IEEE 802.11e-EDCA network under the influence of the Packet Error Rate (PER). Yet, the Packet Fragmentation is the only existing solution since 1999, which allows reducing the influence of the PER on the performance of IEEE 802.11 networks. In this paper, we aim at showing for the first time, how the Packet Fragmentation developed in the legacy IEEE 802.11 standard can be used to enhance the current IEEE 802.11e Quality of Service (QoS). Therefore, we propose an extension of the existing Markov chain models of the IEEE 802.11e EDCA function, in order to take into account the Packet Error Rate and Packet Fragmentation. Furthermore, we develop a mathematical model to derive the saturation throughput of a given Access Category (AC), namely: Voice (VO), Video (VI), Best Effort (BE) and Background (BK). The obtained analytical results show that, applying the Packet Fragmentation on the IEEE 802.11e-EDCA network, allows improving the utilization of the scarce wireless bandwidth under the impact of PER parameters, namely: Bit Error Rate (BER) and packet length.