5 Replies Latest reply on Sep 28, 2018 7:54 AM by mifo

    RSSI of packets received in monitoring mode

    jbl_3106276

      Hi,

       

      Is it possible to get the Received Signal Strength Indication (RSSI) of individual packets received in monitoring mode, i.e. Probe Request, Beacon, etc ?

       

      I've searched the community pages, and I've found questions regarding this dating back to 2015. However, I haven't found any solutions.

       

      Any help is much appreciated.

       

      I'm running:

      WICED version: Wiced_006.002.001.0002

      Chip: CYW43907

       

      /Jesper

        • 1. Re: RSSI of packets received in monitoring mode
          zhez

          Hello:

           

                I just use a sniffer to check the signal level value,  I found the signal value is  stable relatively . I have checked probe request,  QoS null,  80211 Auth , 80211 BAR .  So our get_rssi function should match your request.

          • 2. Re: RSSI of packets received in monitoring mode
            jbl_3106276

            Could you elaborate a little on the exact API function you are referring to?

             

            Remember I have the device running in monitoring mode. What I have is roughly based on the example 'snip.packet_filter'.

             

            I've registered a callback function to process packets with:

             

            wwd_wifi_set_raw_packet_processor( raw_packet_callback );

             

            and enabled monitoring mode with:

             

            wwd_wifi_enable_monitor_mode();

             

            The callback looks like this:

             

            static void raw_packet_callback( wiced_buffer_t buffer, wwd_interface_t interface ) {

                UNUSED_PARAMETER( interface );

             

                void *raw = host_buffer_get_current_piece_data_pointer( buffer );

             

                // Here I'd like to register the devices active on the WIFI channel

                // Specifically I want to register their signal strength

             

                host_buffer_release( buffer, WWD_NETWORK_RX );

            }

             

            If I try to use the API function  wwd_wifi_get_rssi in the callback the return value is a TIMEOUT.

             

            /Jesper

            • 3. Re: RSSI of packets received in monitoring mode
              zhez

              Hi:

                     I think you need a packet radiotap info which includes signal Level . we can see it from wireshark capture .  Unfortunately I can't find any interface that indicates what we capture already includes the radiotap info. 

              1 of 2 people found this helpful
              • 4. Re: RSSI of packets received in monitoring mode
                jbl_3106276

                Radiotap info is exactly what I need, however the only reference to radiotap in the entire SDK is a single header file. This file is, however, not used anywhere in the SDK, and there is no documentation on how to get/enable radiotap information.

                 

                Has anyone made use of radiotap info on the Cypress platform?

                 

                /Jesper

                • 5. Re: RSSI of packets received in monitoring mode
                  mifo

                  Radiotap headers are not supported within the Broad Market.