When you check my feedbacks, you will recognize, that I did such projects already in the past.
And also in combination with mobile WiFi-hotspots in public transportation,to acquire passenger data.
I deliver complete openwrt-build system, plus all source code, of course, and flashable image.
Bid _excludes_ any documentation, as this is a very vague area.
My bid also includes basic PHP-code for server, to store info about detected devices into mysql on server. Server provided by buyer, ubuntu preferred. Can be small VPS, like from [login to view URL]
However, your budget is too low for me.