[USRP-users] How to calculate packets live from USRPN200 hardware

Marcus Müller marcus.mueller at ettus.com
Tue Mar 29 11:19:13 EDT 2016


I'm utterly confused. What do the LEDs have to do with anything?

To be honest, I think this discussion isn't really helping either side;
I can offer you to contact me in private if you want to continue this
topic. As it is now, I'm not getting more understanding of what you're
looking at, and I doubt anyone else here on the list is either :(

What I find really really helpful in situations like these is to take
paper and pencils or your favourite graphics software, and draw some
kind of diagram of the system you're looking out. Using different
kind/colors of arrows (and defining what does mean!) draw in the
relationships between the different parts of the system, so that we have
some basis to talk about.

Best regards,
Marcus

On 29.03.2016 17:07, Mariam Musavi wrote:
> Hi Marcus!
> LED A: transmitting
> LED C: receiving
>
> On Tue, Mar 29, 2016 at 7:14 PM, Marcus Müller
> <marcus.mueller at ettus.com <mailto:marcus.mueller at ettus.com>> wrote:
>
>     Mariam,
>
>     as mentioned, "throughput" is a very high-level concept.
>
>     At the physical layer, where we're currently discussing, you can
>     only *select* a given bandwidth/modulation/coding combination and
>     hence *set* the throughput.
>     This selection of methods and parameters depends alone on how you
>     want your system to behave, and how you model your channel.
>
>     As said multiple times now, you're the one defining bit rate, and
>     your channel and the methods used will lead to an error rate.
>     There's nothing that one can do to predict/measure throughput "in
>     general"; all depends on your system design.
>
>     Best regards,
>     marcus
>
>
>     On 29.03.2016 15:17, Mariam Musavi wrote:
>>     Hi Marcus!
>>
>>     I am really sorry that i couldn't elucidate my problem clearly to
>>     the USRP community, i agree with the point that USRP only knows
>>     the language of waveform. My problem is i simulate a noise to
>>     provide to USRP node. Since i feed that simulated noise to USRP,
>>     it will response to that noise resulting (lower SNR), providing
>>     less throughput. i basically want to measure the throughput of
>>     each node while sending (video data) waveform in the presence of
>>     simulated noise. Is there any block in GRC/USRP which can measure
>>     the throughput in hop-to-hop manner of each node from USRP source
>>     to USRP destination?  
>>
>>     Let me know Marcus if the problem is still unclear!
>>
>>     Thanks.
>>
>>     On Tue, Mar 29, 2016 at 6:01 PM, Marcus Müller
>>     <marcus.mueller at ettus.com <mailto:marcus.mueller at ettus.com>> wrote:
>>
>>         Mariam,
>>
>>         the point still is that the USRP really doesn't know (and
>>         care) what your samples mean. To the USRP, these are just
>>         relative voltage values.
>>         The fact that it's data is up to your software's
>>         interpretation of these values; you can't transmit "bits"
>>         over the air, but you can transmit a waveform that can be
>>         interpreted as such.
>>
>>         So, a USRP can't forward "data"; it just receives RF signal,
>>         makes a digital signal out of it, gives that to a PC, which
>>         might then do something with that, eg. take the same digital
>>         numbers and give it to a USRP to make a TX signal out of it.
>>
>>         I'm having a bit of a hard time understanding in what kind of
>>         "deadlock" you are. That is probably because I don't
>>         understand you correctly; could you explain your problem?
>>
>>         Best regards,
>>         Marcus
>>
>>
>>         On 29.03.2016 14:40, Mariam Musavi wrote:
>>>         video data packets.
>>>
>>>         On Tue, Mar 29, 2016 at 4:17 PM, Marcus Müller
>>>         <marcus.mueller at ettus.com <mailto:marcus.mueller at ettus.com>>
>>>         wrote:
>>>
>>>             Hi Mariam,
>>>
>>>             what packets are you referring to?
>>>
>>>             Best regards,
>>>             Marcus
>>>
>>>
>>>             On 29.03.2016 12:06, Mariam Musavi wrote:
>>>>             Greetings!
>>>>
>>>>             All users,
>>>>
>>>>             I am working on USRP Network series N200, and i am
>>>>             stuck up in the deadlock to calculate packets
>>>>             sent/received during transmission from USRP node. There
>>>>             are two cases:
>>>>
>>>>             1. Calculate packets offline (end-to-end): if i want to
>>>>             calculate end-to-end packet delivery, i used
>>>>             third-party Network Analyzer software.
>>>>
>>>>             2. Calculate packets online: (hop-to-hop) but since i
>>>>             want to calculate real-time packets sent/received from
>>>>             USRP source node to USRP destination node.
>>>>
>>>>             For instance, the network scenario is described as
>>>>             setting up three USRPs that are connected to a computer
>>>>             through ethernet switch. USRP source node forwards data
>>>>             packets (or video) to second USRP (i.e., relay node)
>>>>             and finally the second USRP  forwards the data packets
>>>>             to USRP destination node. For transmission of packets i
>>>>             use a video file.
>>>>
>>>>             Looking forward for help. Thanks.
>>>
>>>
>>
>>
>>
>>
>>     -- 
>>     Syed Mariam 
>>     Graduate Research Assistant
>>     Sunway University (Malaysia) & Lancaster University
>>     (UK) joint program.
>
>
>
>
> -- 
> Syed Mariam 
> Graduate Research Assistant
> Sunway University (Malaysia) & Lancaster University
> (UK) joint program.

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