Simulation study of the influence of hidden stations for the quality of service in the IEEE802.11e WLAN

The new IEEE 802.11 standard version, denoted by 802.11e, was developed in order to introduce mechanisms enabling handling of real time applications in the network. The proper work of the EDCF protocol is influenced by the presence of hidden stations in the network. These nodes may produce a significant increase of the number of collisions. The first part of this paper contains short descriptions of the traditional and modified methods of control of access to the transmission channel. The presented results of simulation tests make possible to determine the influence of the presence of a hidden station for the performances of the entire system and the efficiency of the EDCF mechanism. In the summary we have presented the most important conclusions from the experiments that has been performed.