I have been
using srsLTE for about 5 years now, and about 3 years ago
physical USIM support was added to it.
Did you really mean srsLTE as in network side, or did you mean srsUE
for LTE UE side? The latter seems to make a lot more sense for USIM
support.
srsLTE is the global project (
https://github.com/srslte/srslte )
and it encompasses srsENB / srsEPC for the network side, srsUE for the
mobile side along with a bunch of utility internal libraries shared
between those components.
Rgds,
Sylvain