publserver to time synchronize 2 drive test laptops doing Mobile-to-Mobile test calls

[punto]

Hi dear friends,

please, advise me , which method to use to have

Which server to use to have best - time synchronized - 2 drive test laptops , in two different towns, doing Mobile-to-Mobile test calls
Example/case of having 2 drive test laptops with phones in two different towns is just example , to better understand question
Synch is needed for later on analysis and checking the layer 3 messages, connecting A and B side of the test phone calls

I think there was some international public server used for time synch, isnt it ?
Thanks , P

[punto]

Hi,
Please, can you add some comment from your experience, please ?
Thanks,
P