This paper is focused on the Quality of Service (QoS) for the newest standards of WLAN (Wireless Local Area Network); 802.11g and 802.11n. QoS refers to the possibility of networks to offer different services. The QoS is needed in WLANs, because there is an evolution of the customer's needs for different applications. Oldest WLAN standards were used only for transmission of low bandwidth traffic. Now, with introduction of newest standards, such as 802.11g/n, there is possibility to transmit also the high bandwidth traffic, such as video traffic. This paper analyzes the performance of these standards setting up 4 different scenarios under the same OPNET (Riverbed) project. In these scenarios, are analyzed the differences between 802.11g and n standards, as well as the impact of RTS/CTS (Request To Send/Clear To Send) for improving performance. Network performance for each scenario has been evaluated in terms of data dropped due to buffer overflow (in bps) and media access delay (s).
