Help me calculate RF link budget for a tetra network

Hello everybody,
I have to calculate the rf link budget for a tetra network in order to determine cell radious in several environments (urban, mean-urban.. and so on).

It should be detailed (taking into account UE noise floor, BTS noise...usual stuff) for uplink and downlink.

Could anybody help?

I also need to specify a good propagation model (is there a standard model?) to use and everything else could be useful for the network planning activity.

Thanks in advance.
HI