Here's something that has repeated a number of times in recent wireless history: As described in an Alcatel presentation from 2006 and confirmed by 3GPP here, the first meeting held on LTE was in November 2004 in Toronto. From today's perspective, 6 years from the first meeting (*) to deployment of first networks in the field is a pretty good accomplishment. What is even more amazing to me is that back in November 2004, I didn't even have a UMTS phone yet, I only bought my first one in December that year. Networks where only at the beginning of their rollout and mobile devices were still rare. In other words, most people in that meeting at the time also didn't have a UMTS phone. And yet, they were already thinking ahead about what will come after what they didn't have yet.
(*) there were investigations before that meeting of how OFDM could be used to extend 3G but these activities concentrated on the air interface only from what I can tell.