The AP (Access Point) serves as the base station within a WLAN, terminating the air interface on the network side. They provide the link between the wireless world of 802.11 and the wired world of technologies such as Ethernet. They may also play a bridging function ensuring only traffic destined for a Station is transmitted across the Wireless Medium. This prevents information from being broadcast around the wireless element of the network at the expense of data throughput. Access Points can also perform other functions, e.g. manage QoS (Quality of Service) and take/provide measurements for roaming.