Hi,
I have a use case similar to the one mentioned in this series of
posts:
http://lists.gnu.org/archive/html/discuss-gnuradio/2013-04/msg00421.html
I am using B200-mini with gnuradio flowgraph containing tx and
rx parts. Transmit part contains a udp source block connected to
a physical layer block(that processes channel encoded bits) and
that is connected to a uhd sink block. Receive part has similar
structure with uhd source, phy block and Socket Pdu block.
The transmit part should send data continuously to B200-mini. So
there should be signal broadcasted all the time.(Think of it
like a base station broadcast signal) To achieve this, the upper
layer of gnuradio flowgraph sends packets periodically to
gnuradio.
The receive part has very low latency when i measure with a
known signal( from a test instrument).
When using both transmit and receive parts, I measure the time
passed between the moment a packet enters the udp source block
on transmit side and the moment the same packet sent out from
the receive part of the flowgraph to upper layer. The time
passed changes between 150 to 300 ms for each run of the
flowgraph. These numbers are for GR_FIXED_BUFFER_SIZE decreased
to 2048. With default value of 32k, the time passed is around
2-3 seconds.
I have three questions:
1) What to do to fix the latency so that it does not change each
time the flowgraph is run?
2) Can I decrease latency below the measured values?
3) Can B200-mini send ack packets for send calls, when there is
no sob/eob flags are used?
If anyone previously dealt with a similar use case can offer
alternative methods, it would be great!
Thanks in advance,
Murat