i guess they now realize that CDMA was a big mistake.
First off, LTE is not for GSM only. That's a common misconception. LTE is the 4G path for both GSM and CDMA-2000 carriers. Heck, Verizon did more early R&D and commitment to LTE than the GSM carriers in the USA.
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Secondly, CDMA radios were far superior to the TDMA radios that GSM started with. Engineers knew from the early 1990s that everyone would be moving to CDMA radios for 3G later on.
That's why the countries and companies with money started with CDMA. And sure enough, when it came time to add EVDO-3G, the CDMA carriers had comparatively little to do. They could continue to use their original setup with relatively minor updates.
On the other hand, GSM carriers had to add a second radio type to both their towers and phones for UMTS-3G. Now they required both TDMA and WCDMA radios. Moreover, WCDMA towers need a different arrangement. That's why AT&T was years behind Verizon deploying 3G. To many, though, this was offset by the fact that UMTS-3G over WCDMA could handle voice+data.
(As with LTE, UMTS-3G is not a GSM carrier only protocol. CDMA-2000 carriers in Korea, for example, supported both EVDO-3G and UMTS-3G.)
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When LTE came along, GSM carriers had to support THREE air methods in their towers and phones. TDMA for 2G voice/EDGE. WCDMA for 3G. FDMA for LTE.
CDMA-2000 carriers only needed two radio types. CDMA and FDMA.
Hopefully, one day everyone can move to just one radio for LTE. This should make for cheaper phones and maybe even cheaper phone bills.
