When it comes to LTE-Advanced, virtualization, next-generation application development and more, SK Telecom is typically months -- if not years -- ahead of the competition.

That's also true for small cells. The South Korean operator has been pushing the limits of the mini-base stations for the past few years, achieving many significant milestones in 2014 alone. Courtesy of an update from SK Telecom (Nasdaq: SKM), here are the operator's small cells highlights from the past year, which should give us all some clues about where it's headed in 2015. (See SK Telecom, Samsung Turn on Tri-Band LTE-A and Small Cell Movers & Shakers: Update.)

For more on advances in mobile networks technology, visit our dedicated LTE section here on Light Reading.

February 2014
SK Telecom completed development of key cell virtualization technologies, such as Virtual One Cell (first unveiled at Mobile World Congress 2013) and Inter-site Carrier Aggregation. Both are part of the operator's three-phase SUPER Cell network evolution strategy that is due to be in commercial use in 2016: Virtual One Cell is Phase 1; Inter-site Carrier Aggregation (also known as Elastic Cell or Flexible Cell) is Phase 2; and Hierarchy Cell is Phase 3. SK Telecom showcased the technologies underpinning Phases 1 and 2 at Mobile World Congress in 2014. Through SUPER Cell, the carrier aims to increase capacity by nearly 100 times (through higher radio resource efficiency and more cell splitting and frequency bands) and reduce operational costs by 90%. (See SKT Preps Superfast LTE Demo for MWC.)

February 2014
SK Telecom, together with partner Broadcom Corp. (Nasdaq: BRCM), demonstrated an advanced Carrier Aggregation (CA) femtocell solution for 4G LTE-Advanced small cells at the chip vendor's MWC booth. Built on Broadcom's small cell SoC (system-on-chip) technology, the LTE-Advanced small cell solution will enable SK Telecom to deliver 2x faster data throughput to its subscribers. (See SK Telecom Boosts LTE-Advanced to 225 Mbit/s.)

June 2014
SK Telecom's LTE small cell technology was recognized at the Small Cell Industry Awards, held in London, for the third year in a row. In 2014, SK Telecom was a winner in the 'Innovation in Commercial Deployment' category for its development of new LTE small cell solutions and deployment improvements.

July 7, 2014
SK Telecom signed a memorandum of understanding (MOU) with Ericsson AB (Nasdaq: ERIC) for joint research related to 5G technologies. The two companies initially selected technologies considered essential for the evolution to 5G, including next generation small cell, ultra-wideband, low latency technology that could be used for remote driving, FDD/TDD convergence technology, and more. (See SK Telecom, Ericsson Collaborate on 5G Research.)

July 21, 2014
In a world first, SK Telecom successfully demonstrated Elastic Cell (Inter-site Carrier Aggregation/Flexible Cell) capabilities with Ericsson. The technology is expected to become a key enabler for 5G. Elastic Cell enables multiple cells within range of a handset to cooperate for every transmission, thereby creating a user-centric environment, compared with the current cell-centric environment in which each handset communicates with only one specific cell. (See SK Telecom Trials 'Elastic Cell' With Ericsson.)

October 2014
SK Telecom published a white paper on 5G that suggested a new direction for the technological evolution to 5G. Using 2020 as the start of the 5G era, the white paper details the vision, core technologies, services, requirements and spectrum needed to achieve the next generation of mobile broadband, from the perspective of the users as well as the network operators. SK Telecom suggested User Experience, Connectivity, Intelligence, Efficiency and Reliability as the five values that underpin the evolution to 5G. (See SK Telecom, Samsung Team Up on 5G R&D and Ericsson-LG, SKT Team on 5G, NFV R&D.)

Looking forward, SK Telecom plans to lead the industry's evolution to the next generation of technologies and services by using its role as a chair company of the 5G Forum in Korea to accelerate industry activities and expanding cooperation with global telecoms vendors. (See NGMN Kickstarts 5G Initiative.)

— Sarah Reedy, Senior Editor, Light Reading