A comparison of stop-and-wait and go-back-N ARQ schemes for IEEE 802.11e wireless infrared networks

The upcoming IEEE 802.11e standard adds a new optional acknowledgment scheme, which is called Burst Acknowledgment (BurstAck) in order to support Quality of Service (QoS) and better utilization of the wireless medium (WM). In this paper the efficiency of the well-known Stop-and-Wait (SW) mechanism and the enhanced Burst Acknowledgment (BurstAck) behavior, utilized as a Go-Back-N (GBN) Automatic Repeat Request (ARQ) scheme with Sliding Window is studied. Link parameters such as, the window size of the transmitted MAC protocol data units (MPDUs), the number of stations, (STAs) the frame error rate (FER) and the signal to noise ratio (SNR) are considered. In our analysis, the specific characteristics of the infrared physical layer as well as the 802.11 Management Information Base (MIB) parameters for infrared wireless LANs and the complex behavior of 802.11 MAC protocol are taken into account. The results obtained indicate that BurstAck utilized as GBN performs better for medium sized networks with large window size and not very high FER. However, for small window size, bad channel quality and large networks the GBN scheme is not suggested.