One important component of Themyscira Wireless system sw, specifically
themwi-mgw, implements speech transcoding between GSM codecs on the inside and
G.711 on the outside.  This essential function creates a dependency on some
specialized libraries that implement the codecs which need to be supported.
The following codec libraries are currently required:

1) libgsm, the original GSM 06.10 implementation from 1990s;

2) gsm-codec-lib developed by Mother Mychaela for Themyscira Wireless:

https://www.freecalypso.org/hg/gsm-codec-lib/

This gsm-codec-lib collection provides two libraries: libgsmefr and libgsmfrp.
Both of these libraries are used by themwi-mgw as mandatory dependencies.