Josh, This is great! Although it goes without saying, I'm assuming users should also need to keep in mind that there's no magic going on here w.r.t. gigE bandwidth (i.e., one U2 running "wide open" can pretty much consume an entire gigE port. Now that you've got 2 U2's sharing a single connection each one (on average) should be run at no more than 1/2 max bandwidth). right? --Bob >-----Original Message----- >From: Josh Blum [mailto:josh@joshknows.com] >Sent: Monday, December 13, 2010 07:34 PM >To: Discuss-gnuradio@gnu.org, usrp-users@lists.ettus.com >Subject: [Discuss-gnuradio] UHD Announcement - December 13th 2010 - MIMO cable support > >Hello list, > >I would like to announce support for the MIMO cable with UHD. The >support is experimental, so its not in the mainline yet, and is only >available for USRP2 at the moment. > >The source for the FPGA code has not yet been pushed but you can get the >pre-built images here: >http://www.ettus.com/downloads/uhd_images/experimental/UHD-mimo-cable-support/ > >The supporting host code is available on the packet_router branch of the >uhd repo: >http://code.ettus.com/redmine/ettus/projects/uhd/repository/show?rev=packet_router > >Here is an excerpt from the docs on the MIMO cable in UHD: > >> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >> MIMO cable configuration >> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >> Using the MIMO cable, two USRP devices can be grouped together in a multi-device configuration. >> Only one device in the configuration can be attached to the ethernet. >> This device will be referred to as the master, and the other device, the slave. >> >> * The master provides reference clock and time synchronization to the slave. >> * All data passing between the host and the slave is routed over the MIMO cable. >> * Both master and slave must have different IPv4 addresses but in the same subnet. >> * The master and slave may be used individually or in a multi-device configuration. > >I hope that explains it. Feedback is welcome! > >Thanks, >-Josh > >_______________________________________________ >Discuss-gnuradio mailing list >Discuss-gnuradio@gnu.org >http://lists.gnu.org/mailman/listinfo/discuss-gnuradio >

On 12/13/2010 05:04 PM, bobb@sigmatix.com wrote: > Josh, > > This is great! > > Although it goes without saying, I'm assuming users should also need > to keep in mind that there's no magic going on here w.r.t. gigE > bandwidth (i.e., one U2 running "wide open" can pretty much consume > an entire gigE port. Now that you've got 2 U2's sharing a single > connection each one (on average) should be run at no more than 1/2 > max bandwidth). right? Correct, the max rate of the dual setup would be half that of a single unit. -Josh

On 12/13/2010 05:28 PM, Josh Blum wrote: > > > On 12/13/2010 05:04 PM, bobb@sigmatix.com wrote: >> Josh, >> >> This is great! >> >> Although it goes without saying, I'm assuming users should also need >> to keep in mind that there's no magic going on here w.r.t. gigE >> bandwidth (i.e., one U2 running "wide open" can pretty much consume >> an entire gigE port. Now that you've got 2 U2's sharing a single >> connection each one (on average) should be run at no more than 1/2 >> max bandwidth). right? > > Correct, the max rate of the dual setup would be half that of a single > unit. -Josh It will also be possible to connect both devices to their own dedicated ethernet while sharing the mimo cable, and tell one device mimo_sync=1. In that way you can get the full bandwidth (if your pc allows it), and use the mimo cable only for synchronization purposes. -Josh