Japanese cellco aims to deploy next generation networks in 2020, even though it is unclear what they will look like
Docomo was so far ahead in 3G that - ill-advisedly perhaps - it launched its own pre-standard version, FOMA. It was also in the vanguard of R&D for 4G, feeding into LTE standards and testing gigabit systems way back in early 2011. It works closely with selected vendors to steer them in its preferred directions and tap into their combined R&D resources, an approach now matched by China Mobile. And it is doing the same for '5G', working on experimental trials with six partners.
These partners include Docomo's long term Japanese allies, NEC and Fujitsu, which are well versed in supporting the cellco's R&D directions and, even in commercial scenarios, customizing equipment to ensure the operator can be early to market. The others are the major LTE OEMs - Ericsson, Alcatel-Lucent, Nokia and Samsung - but notably excluding Huawei and ZTE. That may reflect some of the same concerns about Chinese suppliers that the US has cited - officially on the grounds of national security, but perhaps really because of commercial fear - or a revival of the old competitiveness between Chinese and Japanese technology programs.
The basic aim of Docomo's project is to get peak speeds to 10Gbps and above with very high availability and very low latency. The carrier wants the resulting systems to be commercially deployable in 2020.
The six partners will carry out experiments in parallel, with Docomo as the coordinating force. The particular focus is to test and confirm the potential for access networks running in high frequency spectrum, above 6GHz, but potentially up in millimeter wave ranges of 70GHz or 80GHz. This could theoretically support very dense, high capacity networks of very small cells.
In January, Docomo signed a memorandum of understanding with Nokia to explore the potential of the 70GHz band, with plans for an experimental 5G proof of concept system. This is being implemented using National Instrument's (NI) baseband modules which currently make up the system for rapid prototyping of 5G air interfaces.
Ericsson said it would focus on the 15GHz band in its Docomo cooperation, as well as HetNet and antenna advances. And NEC's particular activity will be to verify enhanced time-domain beamforming technologies, supporting very large numbers of antennas for small cells. This could improve Multiuser MIMO approaches to accelerating speeds, reducing interference and boosting capacity.