Multiple networks with particle

Hello,

A friend of my, asked me to help with developing a wireless network for robots in a solar-panel field. Every grid (200x200 meter) should have 1 access point and 8 robots. There are approx. 500 grids connected to each other. So in total, the solar panel field is 200 meter x 100 kilometer.
Only the robots in grid X should communicate with accesspoint in grid X. At the end, there will be +/- 500 independent networks.
The coverage for the AP and robots should be 150 meter. the max LOS distance will be 100 meter. The reason to use WIFI is that all the collision avoidance is already done by 802.11. When I use generic RF modules, I have to write something by my self.

The only thing I am worries about, is how to “pair” 8 modules with 1 AP so that the AP of grid x+1 which is located 200m further, do not listen to the robots in grid x.

EDIT: One remark, The solar-panel field is located in a dessert, so NO wifi or internet available. The only use of this network is to send status updates from robots to access point. the access point is connected to a PLC or something. (don’t know yet)

Anybody suggestions? thanks in advance.

Are you intending to have one SSID and PWD for all your subnets?
If not, you’ve got a possible solution.

No, during setup, every grid can have there own SSID.
Setup should be something like this below:

                  • | * - - - - - - - -
                  • | - * - - - - - - -
                  • | - - * - - - - - -
                  • | - - - * - - - - -
                    …AP1 <200m> AP2
                  • | - - - - - - * - -
                  • | - - - - - * - - -
                  • | - - - - * - - - -
                  • | - - - - - - - - *
  • = robot, — is the robot track and AP is accesspoint
    | = border between grid x and x+1

Oh, one important requirement, is that the range LOS should be (at least) 100 meter. but 150 meter is preferable.
Is that feasible with just an external antenna?
And in every grid, the Photon needs to act as an access point, but that is no problem I think.