Throughput Estimates for A-MPDU and Block ACK Schemes Using HT-PHY Layer

IEEE 802.11n standard has introduced the new schemes in MAC and HT-PHY layers to improve network throughput. The new schemes in MAC layer are A-MSDU, A-MPDU and Block ACK. In the HT-PHY layer there are MIMO transmission using up to 4 spatial streams, 40 MHz bandwidth channel and 400 ns guard interval. In this paper, we proposed an analytical model that can be used to estimates the throughput of A-MPDU and Block ACK schemes using HT-PHY layer. In our model, there are six different slot types, which are A-MPDU transmission slot, A-MPDU collision slot, A-MPDU sub-frame error slot, BAR error slot and BA error slot. We derive the equations that can be used to calculate the time duration and the probability occurrences of each type slot. Our analytical model also considers the anomalous slot phenomenon in EDCA scheme and frame error probability in HT-PHY. The simulation results using matlab show our analytical model can be used to estimates the throughput of MSDU transmission using A-MPDU and Block ACK schemes. AMPDU and Block ACK schemes can be used to improve the MAC throughput especially for MSDU size is bigger than 400 bytes.