[Discuss-gnuradio] Synchronize USRP in which level

[Gong Zhang]

Hi,
My last topic "Synchronize multiple USRP-N210s"may be a big one which
gives no reply.If I want to synchronize two USRPs without cable or
GPSDO,I should design a synchronization protocol.Simply A sends some
time-stamped samples to B ,then B record local time when receiving these
samples.Knowing the distance between them,we can synchronize B with
A.Apparently the synchronization accuracy depend on we make the
timestamps in which level.Ethernet involve in 10s of microseconds jitter
shows that we should do it on FPGA.Does UHD have this function?
Any comments will be valuable to me.
Thanks.