Hello,
I try to clarify:
(West) Germany:
A-netz: 1952–1977 (160 MHz, custom built, 0G technology, analogue, manual switch)
B-netz: 1972-1994 (150 MHz, custom built, 1G technology, analogue, automatic)
C-netz: 1985–2000 (450 MHz, custom built, 1G technology, analogue + SIM cards)
D-netz: 1991- (900 MHz, GSM, 2G technology, digital)
E-netz: 1994- (1800 MHz, GSM/DCS, 2G technology, digital)
Austria:
A-netz: (same as the German A-netz, but totally marginal)
B-netz: 1974-1995 (same as the German B-netz, with international roaming)
C-netz: 1984-1997 (450 MHz, analogue NMT, 1G technology, like Sweden, Denmark, Switzerland, Hungary etc.)
D-netz: 1990-2002 (900 MHz, analogue ETACS, 1G technology, like UK, Ireland, Italy)
E-netz: 1994- (900 MHz, GSM, 2G technology, digital)
And this is a card for German C-netz: