[en] Currently, broadband wireless access is gaining a great deal of interest from the networking research community. Particularly, the recently standardized WiMAX presents interesting perspectives, notably due to its capacity to offer consistent bandwidth and therefore consistent QoS. However, the behavior of network protocols, such as TCP, has not been studied in detail in a WiMAX environment. This is a problem that could slow down the widespread deployment of WiMAX. In this paper, we present preliminary results of the performance of TCP in a pre-WiMAX network. We are interested in the RTT and the relationship between the delay and packet loss rate. We find that TCP presents an acceptable cyclic behavior but with a high percentage of packet loss, 6.2%. We further notice some burst packet losses that vary in size and duration. Some of these bursts correspond to a packet loss rate of 100% during periods of up to one second.
