For many mobile operators, introducing 4G/LTE technology into their networks is either very new or still in the planning stages.
Not at NTT Docomo Inc.
The Japanese innovator recently reached 10 million subscribers for its LTE service called Xi (pronounced Crossy) and is now looking towards the next step in its technology evolution, LTE-Advanced, with the help of Nokia Siemens Networks and Panasonic Mobile Communications Co. Ltd.
LTE-Advanced is laid out in the 3rd Generation Partnership Project (3GPP) release 10 of the LTE specification, which includes enhancements to base station and device technology to help boost the transmission speeds and spectral efficiency of 4G. In theory, LTE-Advanced can deliver downlink speeds of up to 3 Gbit/s but in commercial operational networks the speeds would be a lot less. (See Meet the Next 4G: LTE-Advanced.)
NSN and Panasonic are to develop LTE-Advanced base station technology, including Remote Radio Head capabilities (no, not "remote Radiohead") for small-cell rollout, for delivery by 2015. NSN's Liquid Radio architecture involves the de-coupling of the antenna and baseband elements of the radio access network (RAN) and having a centralized pool of baseband capacity shared by multiple antennas. (See NSN Hangs Its Future on the Liquid Net.)
While Docomo is usually far ahead of other major operators in terms of technology deployments, it's not alone in looking towards next generation 4G -- in fact, it may find itself in the chasing pack for once, as AT&T Inc. appears to be on course for some sort of LTE-Advanced deployment later this year. (See AT&T Plans LTE-Advanced in 2H13.)
With Docomo giving its vendor partners the green light and a timetable, and AT&T looking to be an early mover, it'll be surprising if there isn't a fair buzz about LTE-Advanced at Mobile World Congress next week, even though 4G is hardly out of the starting blocks…
— Ray Le Maistre, International Managing Editor, Light Reading