Advise on implementing TDMA

Dear All,

I am currently tried to implement TDMA scheme on gnuradio. I found that
openBTS had used the approach but need some hardware modification to get
it
work with GSM network. In my project, hardware modification has to be
avoided hence openBTS solution might not work for me. At the moment, I
tried to implement some time-stamping method using software as USRP1 is
not
supported by UHD driver. Has anyone look this matter? Could anyone at
least
give me an idea where should I start?

USRP1 is fully supported by UHD.

I should clarify, sorry, I just shot that off without reading. USRP1
can’t do sample timestamps like USRP2/N210/E100/B100.