| Popis: |
Frame delay variance in CSMA/CA networks is large. Wireless applications may require both, limited mean delay and limited delay jitter. These parameters can be derived easily from cumulative distribution function (CDF) of frame delay. This paper applies Signal Flow Graphs (SFGs) to calculate the CDF of frame delay in IEEE 802.11 DCF WLANs. SFGs allow to establish a mathematical WLAN model for precise numerical calculation of frame delay based on generating functions. Both, medium reservation based on RTS/CTS and no reservation are studied and link adaptation is taken into account, too. Stations are assumed to always have a frame waiting for transmission. Our mathematical analysis results are compared for typical WLAN application scenarios to simulation results gained from the openWNS system level simulator. |
