The latency is an issue when action of one side is dependent on reaction of the other side. Usually there are narrow time limits that have to be considered, and the time an action travels over USB or Ethernet may simply be to long. The other thing may be jitter, many protocols do not like variations in the timing, but those are more or less normal for USB or Ethernet. The closest binding between hardware and controller is doing it all in the FPGA, what could be considered as a real time system.
Ralph. From: [email protected] [mailto:[email protected]] On Behalf Of Mostafa Alizadeh Sent: Tuesday, January 13, 2015 2:44 PM To: Jeff Long Cc: [email protected] Subject: Re: [Discuss-gnuradio] Bluetooth Transmitter using GRC Yeah I have had a look at Bluetooth PHY. The hop rate of Bluetooth in paging substate increases as 3200 hop/sec too. So you mean the N210 USRP can't support 1600 (or 3200) hop/sec? What do you mean by "latency"? Is that the latency of the USB or Ethernet? Jeff, please clarify your stance. Why the latency problem doesn't matter X-series USRP? Best, Mostafa On Tue, Jan 13, 2015 at 3:02 PM, Jeff Long <[email protected] <mailto:[email protected]> > wrote: On 01/12/2015 01:07 PM, Mostafa Alizadeh wrote: Hi Jeff, What is your reason for saying: "Latency and tuning" of the N210 device isn't appropriate??? I should have said that, with either USB or Ethernet, and with a non-real-time O/S, the latency to too great. Hop rate is generally 1600 hops/sec. Take a look at the Bluetooth physical layer spec for more info. Best, Mostafa On Mon, Jan 12, 2015 at 2:52 PM, Jeff Long <[email protected] <mailto:[email protected]> <mailto:[email protected] <mailto:[email protected]> >> wrote: On 01/10/2015 02:46 PM, vaibhav kulkarni wrote: Hi All, I am searching for an implementation of a complete Bluetooth stack on GRC 3.7 ( Including the Bluetooth Transmitter and Receiver) preferably working with USRP N210. So far I got this "gr-Bluetooth, Bluetooth for You could build one in the FPGA of an X-series box. Latency and tuning requirements exceed what you can do with a N210. GNU Radio" (http://gr-bluetooth.__sourceforge.net/ <http://sourceforge.net/> <http://gr-bluetooth.sourceforge.net/>), However it is not a complete stack and I guess it doesent include the Bluetooth Transmitter. I built it and checked but couldn't find one. Can you suggest any existing implementation of complete Bluetooth stack ? Any Help is appreciated. Regards, Vaibhav _________________________________________________ Discuss-gnuradio mailing list [email protected] <mailto:[email protected]> <mailto:[email protected] <mailto:[email protected]> > https://lists.gnu.org/mailman/__listinfo/discuss-gnuradio <https://lists.gnu.org/mailman/listinfo/discuss-gnuradio> _________________________________________________ Discuss-gnuradio mailing list [email protected] <mailto:[email protected]> <mailto:[email protected] <mailto:[email protected]> > https://lists.gnu.org/mailman/__listinfo/discuss-gnuradio <https://lists.gnu.org/mailman/listinfo/discuss-gnuradio> -- *********************************************************** Department of Electrical Engineering Aboureyhan Building MMWCL LAB Amirkabir University Of Technology Tehran IRAN Tel: +98 (919) 158-7730 LAB: http://ele.aut.ac.ir/~mmwcl/?page_id=411 Homepage: http://ele.aut.ac.ir/~alizadeh/ *********************************************************** _______________________________________________ Discuss-gnuradio mailing list [email protected] <mailto:[email protected]> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio -- *********************************************************** Department of Electrical Engineering Aboureyhan Building MMWCL LAB Amirkabir University Of Technology Tehran IRAN Tel: +98 (919) 158-7730 LAB: http://ele.aut.ac.ir/~mmwcl/?page_id=411 Homepage: http://ele.aut.ac.ir/~alizadeh/ ***********************************************************
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