Hi, On 10/03/2011 04:57 PM, Kai Zeng wrote: > Thank you for the reply. The new N200 series use Gigabit Ethernet > cable to connect the board and the host, so will it decrease the delay > to satisfy the precision in tens of microsecond? I have taken a look > at the paper. It seems the delay between the GNU radio in the > userspace and FPGA is large. Does it mean, even with the Gigabit > Ethernet port, the MAC delay is hardly to satisfy? Unfortuntely, yes. In terms of host<->RF front end delay, the USRP2 is not really an improvement over the USRP1. The E100 should perform better but the GPP performance is very bad. Exploiting the DSP and/or FPGA and/or the vector extensions of the ARM could help here. But I am not aware of any actual implementation though. Anybody else? Regards, Andre

We use the 8b/10b serdes port to do 80211.g on another FPGA (not the small FPGA on the USRP) using the USRP as a frontend. Documentation here: airblue.csail.mit.edu Doing 80211.g in software is quite difficult. The SORA project managed to do it, but it took some serious hacking and building custom hardware. -Elliott Quoting "Andre Puschmann" <andre.puschmann@tu-ilmenau.de>: > Hi, > > On 10/03/2011 04:57 PM, Kai Zeng wrote: >> Thank you for the reply. The new N200 series use Gigabit Ethernet >> cable to connect the board and the host, so will it decrease the delay >> to satisfy the precision in tens of microsecond? I have taken a look >> at the paper. It seems the delay between the GNU radio in the >> userspace and FPGA is large. Does it mean, even with the Gigabit >> Ethernet port, the MAC delay is hardly to satisfy? > > Unfortuntely, yes. In terms of host<->RF front end delay, the USRP2 > is not really an improvement over the USRP1. The E100 should perform > better but the GPP performance is very bad. Exploiting the DSP > and/or FPGA and/or the vector extensions of the ARM could help here. > But I am not aware of any actual implementation though. Anybody else? > > Regards, > Andre > > _______________________________________________ > USRP-users mailing list > USRP-users@lists.ettus.com > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >