An overhead analysis of Access Network Query Protocol (ANQP) in hotspot 2.0 Wi-Fi networks

With the increasing popularity of WI-FI CERTIFIED Passpoint(TM) program many hotspot owners look forward to installing new Hotspot 2.0 equipment into their networks. Access Network Query Protocol (ANQP) is used by a subscriber station (SS) in Hotspot 2.0 technology for selecting the network before association with an access point (AP). It simplifies the network selection and discovery mechanisms from the user´s point of view. On the other hand this technology uses some new management frame elements, which cause additional airtime overhead in Wi-Fi network. This paper analyzes the overhead caused by new elements in Beacon and Probe Response frames. It shows the increasing airtime as a measure of Hotspot 2.0 protocol overhead. It also describes some dependencies between the airtime overhead and number of co-located wireless local area networks (WLAN), number of virtual service set identifiers (SSID), management frames transmission rate.