Experimental Analysis of TCP and UDP Traffic Performance over Infra-structured 802.11b WLANs

In this paper we present the results of experiments carried out in an infra-structured 802.11b WLAN comprising a single Access Point (AP) and a number of user terminals. The aim of this work is twofold: by the one hand, we validate well-known "TCP (UDP) over 802.11" analytic models by means of experimental results; by the other hand, we focus our analysis on TCP behavior over 802.11b. We present results about flow fairness, about interaction between WLAN link layer parameters (ARQ) and transport protocols and about TCP flows traffic characteristics. With respect to earlier related works, an added value of our analysis is given by a more accurate knowledge and control of key parameters that highly affect the system performance (e.g., mobile station transmission bitrate, maximum number of retransmission attempts, TCP version, etc.) that guarantees the reliability of numerical results. This is a key issue in order to confidently explain observed experimental phenomena.