The transition frequency (Ft) of a transistor is the frequency at which the current-gain BETA = unity.
You know Ft depends on the DC bias current of the collector Ic. Ft is maximum for a certain value of Ic.
Now if you want to measur Ft you have first to bias the tansistor : fix the base current and VCE, then perform an AC simulation to plot the current gain Ic/Ib (that is Beta) Vs frequency you will find Ft the frequency that gives 0dB current gain
good luck