Josh B. wrote in post #1026628:
On 10/14/2011 04:46 AM, qaz wsx wrote:
I am planning to move from CSMA to TDMA. Can anyone help me get directions
where to start. I saw that mblock are no more available, and instead ‘stream
used. I don’t have knownledge of the underlying structure.
The gr-uhd sink block can use tags to precisely control timed bursts.
See gr-uhd/examples/tags_demo.cc for an example
Thanks for the reply!
I saw that I can send tags to the USRP. Now here is my problem.
In my TDMA implementation, synchronization preambles have to be sent
periodically. When there is always data to transmit, then 10 packets are
transmitted following the preamble. In this case, stream tags may not be
used; we simply write a block that inserts preambles every 10 packets.
However, it may happen that no much data is avaiable from the MAC layer
so that we don’t have to wait for 10 packets to transmit the preamble.
Now, I am thinking to modify the gr_uhd_sink block so that it inserts
preambles according to timestamp count. This block will not have input
ports (it receives data via message pointer). This makes sure that the
scheduller calles the “work” method even when there is no data (just my
thought). What is your opnion?