Less than two years after launch, the South Korean operator has more than 10 million customers for its 4G LTE service and is expecting to have 15 million by the end of this year. If industry forecasts are in any way accurate, that would give SK Telecom an 8 percent share of the total global 4G user base.

Currently, about one-third of all SK Telecom mobile customers are on LTE packages. The operator ascribes its success to a number of factors, not least that it offers a broad range of devices -- 25 smartphones, five tablet PCs, two USB modems and one LTE-capable camera.

That's not all. The Korean operator plans to launch commercial LTE-Advanced services in September this year, to deliver "faster and more reliable services." (See Why You Should Care About LTE-Advanced (Eventually).)

Evidence of such advances are also to be seen in Japan and the U.S., where Verizon Communications Inc. added 4.7 million LTE subscribers in the first quarter of this year to take its total at the end of March to 26.3 million. Verizon is also now working on the introduction of 4G voice services. (See NTT Docomo Hits 10M LTE Subs and Verizon Promises Voice-Over-LTE in 2014.)

How about Europe? Ask again in another few years. The region is suffering from a toxic combination of ongoing economic woes (the so-called "eurozone crisis" is not going away), hold-ups in license awards and a large number of mobile operators with little appetite for antagonizing their shareholders with talk of increased capital expenditures. The U.K. mobile market leader is deemed aggressive for targeting 1 million 4G customers by the end of 2013. (See EE Gets Smart With Its LTE Assets.)

There was a time when Europe was keeping pace with other parts of the world in terms of mobile deployment developments -- that seems like a long time ago.

— Ray Le Maistre, Editor-in-Chief, Light Reading