Tuesday Trivia

The answer to yesterday's question is:
The Flamingo Kid (1984) was the first film to receive the rating, but was not released until December 1984. The first film distributed with a PG-13 rating was Red Dawn (1984). Dreamscape and The Woman in Red were released on the same day the following week.

Today's question is:
On commercials for cell phone carriers we often hear reference to 3G and 4G technologies. Going back in time somewhat, what was the difference between 1G and 2G technologies?