Calculate the probability of collisions in an RF system?

[dvash]

Dear Sirs,

I have a question in probability which i hope you can help me
with:

In a building there are N number of transmitters. Each such unit
transmits every 5 minutes a transmission that lasts 0.03 seconds.

My question is: In one hour, what is the chance that a collision
will happen between 2 or more transmitting units?

It should be noted that each unit has a separate time base that
counts the 5 minutes, meaning the transmission of
a unit within the 5 minutes envelope is totally random with
relation to other units.

Thank you very much in advance!

Nir Dvash,

[Dason]

So are the transmissions sent exactly 5 minutes apart from one another? Or does the device choose sometime in a 5 minute interval based on (I'm assuming a uniform) distribution. Then does the same for the next 5 minute interval...

[dvash]

Hi Dason,

Thank you for your note. When installing the trans. unit, the battery is
inserted and then the unit counts 5 minutes and transmits, then another 5 minutes and so on and on. The main point is that the units are installed one by one! They are not sync. in any way!

I hope this helps.

Nir.