Complex sentence: In addition to this, the GImux transport (aka G_MAN) is only available in Greater Manchester and the NImux transport (aka RNI_1) is only available in parts of Northern Ireland.
Split into simpler sentences: In addition to this, the GImux transport (aka G_MAN) is only available in Greater Manchester. The NImux transport (aka RNI_1) is only available in Northern Ireland.