NTT docomo, Japan’s largest mobile phone network provider, in cooperation with the Tokyo Institute of Technology, is currently undertaking research for a new 5G network with the intent of reaching 10 Gbps transmission speeds.
Interestingly, their experiment achieved these speeds using a Multiple-Input and Multiple-Output (MIMO) antenna, a feature common to newer standards, such as HSPA+ and 802.11n. They conducted this test with a 400 MHz block of bandwidth in the 11 GHz spectrum, which is an uncommon frequency to use in mobile phone operations. Super high-frequency bands (5 GHz and higher) are not commonly used for mobile phone communications, due to the difficulty of transmitting those waves around buildings. NTT docomo provided no explanation in their press release about how this limitation will be overcome.
NTT docomo’s research department first proposed the current standard of mobile communications technology, LTE, in 2004. In June, they announced the deployment of a compact LTE base station in locations where traditional base stations cannot be deployed due to prohibitive size or cost, such as mountainous locations.
Currently, NTT docomo service in Japan, branded as Xi LTE, is capable of delivering download speeds up to 100 Mbps. According to a study by PC Magazine, the fastest LTE service in the United States is AT&T, with an average speed of 16.02 Mbps and a maximum speed of 58.25 Mbps. According to a study by Joseph Hanlon at CNET, Australian LTE services on Telstra average 39.97 Mbps. In the United Kingdom, comparable speeds can be found on the fastest LTE service provided by Everything Everywhere (EE), a joint venture between T-Mobile and Orange.
While research in advancing mobile communications technology is a laudable endeavor, this particular experiment isn’t ready for deployment anytime soon. The device being tested wasn’t a handset — it was a “mobile station” (communications truck) moving at 9 km/h (5.5 mph). Accordingly, the power consumption of the components in the truck is likely quite massive, at least in comparison to the painstakingly optimized hardware of the phone in your pocket. For these reasons, it's quite likely that it will be several years — if not a decade — before this technology is used in commercially available consumer mobile phones.
Additionally, the design of a network using super high-frequency bands would need a great deal of engineering to overcome the limitations of that technology. Deployment in Japan would be easier if some workaround is devised for broadcasting around buildings, which in particularly urban places such as Tokyo would be a significant encumbrance to such an endeavor.
Deployment in the United States has a completely different set of problems, however. In addition to having the problem of engineering around a sprawling metropolis, the United States has a great deal of suburban semi-rural areas with particularly low population densities. Engineering a mobile network using super high-frequency bands would be a gargantuan undertaking. NTT docomo’s engineers are likely up to the task, though the question is worth asking: Should a one-size-fits-all solution be used in mobility, or should U.S. carriers stick to technologies that can be deployed with greater ease and at a lower cost for the geographic layout of the United States?
What is your hope for the future of mobile connectivity, and how are your connection speeds where you live? Let us know in the discussion thread below.
James Sanders is a Tokyo-based programmer and technology journalist. Since 2013, he has been a regular contributor to TechRepublic and Tech Pro Research.