Sprint may have spearheaded the use of WiMAX-based mobile broadband services in the US, but the tech-heads in South Korea have been using WiMAX networks, known on that side of the Pacific as “WiBro” (Wireless Broadband), for years now. WiMAX networks promise high-speed wireless data transfers but have traditionally fallen short of providing voice call functionality. Fortunately, that will soon change with South Korea’s ratification of a voice-over-WiMAX standard.

The new protocol, approved by the Korea Communication Commission (KCC), is essentially a VoIP (Voice over Internet Protocol) technology. In a bid to draw in more customers to use its WiBro networks, which has seen just 200,000 subscribers since going live in 2006, Korean telecoms are planning to roll out voice-over-WiBro in 2009.

The KCC’s approval of the voice-on-WiMAX standard opens the door to voice call services on Sprint (NYSE: S)’s nationwide WiMAX network in the US. Sprint’s dual-mode CDMA/WiMAX modems allow for voice-calls on Sprint’s CDMA network, but requires subscriptions to two distinct wireless networks - a hassle, at best. The ability to pull down high speed mobile broadband data and make voice calls on the same WiMAX network is not just more convenient, it may just give WiMAX an edge in the US. We could see voice-on-WiMAX technologies giving 4G LTE networks a serious run for its money.