LIVE FROM GSMA MOBILE WORLD CONGRESS SHANGHAI 2015: The telecom industry is abuzz with talk about 5G, even though implementations are years away, with the discussions already focused around use cases, business models and the wider ecosystem, according to the CTOs of leading operators from Japan and South Korea.NTT Docomo CTO Seizo Onoe (pictured) told Mobile World Live that the type of discussions taking place are very different than with 3G and 4G, when the technology came first, which then led to services and new businesses long after deployments. “With 5G the actual technology to support the business cases will come later.”SK Telecom CTO Alex Choi agreed, noting that over the past couple of years the telecoms industry has been in the process of defining the use cases for 5G.“The use cases being discussed span many technology domains and, therefore, it is essential for the different technology domains to share the visions, strategies and use cases for efficient and timely development of 5G networks and services,” Choi said.Because many incremental steps tend to make things more complicated, Onoe said, the telecoms industry needs to take fewer, more significant steps on its road to 5G.The industry should stop the evolution of old technologies after it finds a new one, he said. “This would make things more simple through quicker migration to the new. Actually, I tried to stop HSPA evolution standardisation after LTE had emerged, but I couldn’t and then finally 8x HSPA specifications were created. Thus many steps were created in 3G.”This is not only true for core networks but also for radio networks and device implementations, he said.“5G will need a big step with significant gains for futureproof expandability,” Onoe explained.LTE-Advanced has technical specifications for speeds of over 1Gb/s, which have not yet been implemented, so there is room to enhance current 4G networks, he noted, adding that Docomo will also continue work on the evolution of 4G, while at the same time seeking to provide 1Gb/s services before 2020.“I don’t see the aggressive push to 5G having a negative impact on 4G. We have a concrete plan for the 4G evolution and some 5G features might be implemented over the 4G evolution path, which will help smooth the introduction of 5G.”Docomo is currently conducting trials on basic technologies and demoing the performance of some applications in computer simulations. He expects to see 4K and 8K UHD videos and sensor networks over 5G available for real-time monitoring of athletes in the Tokyo Olympic and Paralympic Games in 2020.Choi said by the end of the year it will focus on setting up a 5G test-bed to identify and verify the feasibility of potential key enabling 5G technologies independently.