Synchronizing multiple USRPs

GNU Radio
1

Hello,

I have eight (08) USRP N210s that has been synchronized using 10MHZ and
1PPS
reference. I am receiving data from them using a gigabit ethernet switch
to
my computer.

My question is when I will receive packets from all of them through a
single
switch, how will I know the time reference for each sample?

Thanks,

Khalid.

2

On 02/27/2011 11:48 PM, Khalid J. wrote:

Hello,

I have eight (08) USRP N210s that has been synchronized using 10MHZ and 1PPS
reference. I am receiving data from them using a gigabit ethernet switch to
my computer.

My question is when I will receive packets from all of them through a single
switch, how will I know the time reference for each sample?

A time stamp can be found in the metadata, representing the time of the
first sample in the packet. See the docs for the recv() call:
http://www.ettus.com/uhd_docs/doxygen/html/classuhd_1_1device.html#a3e7e55ed84ca59310c4396a18a5e36d5

-josh

3

On 02/27/2011 11:48 PM, Khalid J. wrote:

Hello,

I have eight (08) USRP N210s that has been synchronized using 10MHZ and
1PPS reference. I am receiving data from them using a gigabit ethernet
switch to my computer.

My question is when I will receive packets from all of them through a
single switch, how will I know the time reference for each sample?

The packets are all time stamped, and the UHD takes care of
synchronizing everything, so you don’t need to do anything special.

In the future, you don’t need to post to both gnuradio and usrp-users.
Please choose the one which fits your question better.

Thanks,
Matt