title: Counting people using wifi packets when phones have randomized mac ids
body: <p>I want to build a system for counting people based on wifi packets. I am using esp8266 for sniffing packets. But i read that android and iphones are now randomizing mac ids when they are not connected to any network. I thought of using probe requests but i saw that whenever i press refresh in mobile, the mac address is changed. So my program would detect it as a new device. 
  This is what i am getting in different packets from the same device. </p>
  
  <pre><code>Mac Address - da a1 19 9f bb 5c
  d4 10 68 50 00 00 00 00 00 00 05 00 40 00 00 00 ff ff ff ff ff ff **da a1 19 9f bb 5c** ff ff ff ff ff ff e0 a4 00 0b 77 69 66 69 63 68 61 68 69 79 65 01 04 02 04 0b 16 32 08 0c 12 18 24 30 48 60 6c 03 01 04 2d 1a 6e 01 03 ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 dd 07 00 50 f2 08 00 00 00 7f 05 00 00 0a 02 01 3d 16 04 05 01 00 00 00 00 00 00 00 01 00 68 00
  
  Mac Address - da a1 19 00 44 2f
  d3 10 2e 50 00 00 00 00 00 00 0c 00 40 00 00 00 ff ff ff ff ff ff **da a1 19 00 44 2f** ff ff ff ff ff ff 90 c1 00 00 01 08 02 04 0b 16 0c 12 18 24 32 04 30 48 60 6c 00 00 34 34 50 43 01 08 82 84 8b 96 12 24 48 6c 03 01 0b 32 04 0c 18 30 60 07 06 49 4e 20 01 0d 14 23 02 13 00 46 05 f3 c0 01 00 04 05 04 00 01 00 14 dd 1a 00 50 f2 01 01 00 00 50 f2 02 02 00 00 50 f2 02 00 50 01 00 2e 00
  
  Mac Address - da a1 19 ea d3 58
  d7 10 67 50 00 00 00 00 00 00 03 00 40 00 00 00 ff ff ff ff ff ff **da a1 19 ea d3 58** ff ff ff ff ff ff a0 c2 00 0a 5a 54 45 2d 4b 62 72 79 59 47 01 04 02 04 0b 16 32 08 0c 12 18 24 30 48 60 6c 03 01 01 2d 1a 6e 01 03 ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 dd 07 00 50 f2 08 00 00 00 7f 05 00 00 0a 02 01 00 d7 75 eb 1d 7c e1 2f 06 a2 2c a3 df 01 00 67 00
  
  </code></pre>
  
  <p>I don't want to track individual user, my goal is to count the number of people in an area. Can I use any other packet type than probe request ? or will there be some similarity in probe request packets originating from same device, that way I can discard the new packet from the same device even if the source address (mac address) is changed. </p>