Network continuity, however, may not be the driving factor in carriers' decisions to build 4G networks. Sprint already proved that when it chose to deploy WiMAX — a completely separate network over a flat IP architecture that envisions a new set of applications and different portfolio of devices, many of which will not be backwards-compatible to its CDMA network.

And even if a CDMA carrier has continuity in mind, it's not a given that LTE can't provide it. Mark Slater, vice president of sales and marketing for Nokia, said the disruption caused by the migration to 4G and the inherent parity of LTE and UMB performance will overcome the monolithic wall that has divided the CDMA and GSM camps for more than a decade.

“The performance of the technologies is, across the board, very similar,” Slater said. “We really feel it's not a technology choice anymore but a business choice.”

LTE, UMB and WiMAX will share a common flat IP architecture, and in the network core, the 3GPP's development of system architecture evolution (SAE) specification is designed to create a next-generation high-capacity IP core that integrates easily back into legacy networks. The 3GPP is specifically identifying CDMA legacy networks in the SAE standard in order to create a level playing field between CDMA and GSM operators launching LTE. As for handsets, if a vendor can make a dual-mode CDMA/UMB device, it can certainly make a CDMA/LTE device.

The odd man out in this whole debate is Qualcomm. The San Diego chipset-maker first developed CDMA, became the dominating force behind the 3GPP2 and eventually shepherded its technology into the 3GPP, which adopted wideband CDMA. Qualcomm, however, is a CDMA technology, and the transition to 4G seems to be leaving it out of the loop.

To a certain extent, Qualcomm has embraced OFDM — it forms the basis of the Flash-OFDM technology Qualcomm acquired through Flarion Technologies and the transmission means for its FLO multi-cast TV equipment — but according to Cristiano Amon, vice president of CDMA product management for Qualcomm, innovations like interference cancellation and multiple antenna technologies will propel current EV-DO and UMTS high-speed packet access technologies well beyond their current capacity and latency thresholds, Amon said. OFDM may be the technology du jour, Amon said, but everyone in wireless knows how quickly that can change.

“CDMA is quickly approaching the quality of OFDM,” he said. “Investment in CDMA isn't over.”