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.