How to determine the range of the Transmitter of following

How to determine the range of the Transmitter of following http://www.rhydolabz.com/documents/wireless/MO_SAWR.pdf

thanks in advance .

I guess the data is transmitted around 50-100m in a wide area..

Actual range depends on many things, Some things:
-reguired reliability of the link
-Receiver sensitivity
-transmitter and receiver antenna
-height above ground and orientation of receiver and transmitter
-RF environment (obstacles in between?, indoor/outdoor?, etc)
-fixed (point to point) versus mobile use
-local interference
-data rate and coding (think of error correcting or detecting coding).
-supply voltage (large influence on RF output power).

Depending on your situation, you select a certain propagation model to assess the range.