NTT Docomo and EE mapped out their visions for 5G at a press event hosted by Nokia Networks in London on Tuesday, and effectively planted "You are here" signs in this largely uncharted technology territory.
That doesn't mean these operators have 5G all figured out. They don't, of course. But they do have a good idea of where they want to go, and both operators conveyed the sense that their journeys toward 5G have already begun as certain technologies that they are working with now will serve as stepping stones to 5G in the future.
For example, Dr Sadayuki Abeta, NTT DoCoMo Inc. (NYSE: DCM)'s director of radio access network development, pointed to the operator's work with advanced centralized-RAN (C-RAN) architecture for LTE-Advanced carrier aggregation, which is basically carrier aggregation between macrocells and small "add-on" cells to increase network capacity and speed.
"This is an idea you can use in 5G," said Abeta.
DoCoMo has one of the most aggressive plans for 5G with a looming target of having a commercial 5G network up and running for the Tokyo Olympics in July 2020. The operator is testing potential technologies in various spectrum bands with eight vendors, including Nokia Corp. (NYSE: NOK), Alcatel-Lucent (NYSE: ALU), Ericsson AB (Nasdaq: ERIC), Huawei Technologies Co. Ltd. , Samsung Electronics Co. Ltd. (Korea: SEC), Fujitsu Ltd. (Tokyo: 6702; London: FUJ; OTC: FJTSY), Mitsubishi Corp. and NEC Corp. (Tokyo: 6701). (See 5G: Generation Gap, Getting Massive at DoCoMo's 5G Lab, and 5G: Meet the Influencers.)
While DoCoMo believes some of 5G will build on 4G technology developments, new technology will be needed to meet the requirements of massive device connectivity and extremely low-power consumption for Internet of Things (IoT) services.
DoCoMo's vision for 5G includes the use of higher frequency bands, small cells, massive MIMO, new radio access technology (RAT) -- such as the operator's own non-orthogonal multiple access (NOMA) -- as well as the "phantom cell" concept, which enables inter-cell coordination in a small cell overlay architecture. As for spectrum, the operator expects to use a mix of existing frequency bands, new frequencies that will be licensed after 2019, as well as unlicensed bands.
The results so far from DoCoMo's many tests with the eight different vendors haven't yet yielded a definitive answer about which frequency bands are best suited for 5G applications, according to Abeta. "We haven’t decided which frequency band to use for 5G. We're looking at what's technically possible," he said.
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