Fujitsu and DOCOMO in Field Trial to Make Comfortable High-Capacity 5G Communication Available from Everywhere

A distributed antenna system under study (Fujitsu's Kawasaki plant)

Autonomous Driving and Remote Medical Care... What are Requirements for 5G in the Age of IoT?

In recent years, the development of self-driving cars has been actively advanced, and a 5G environment is becoming a prerequisite for allowing drivers to safely navigate to their destinations. Thus, 5G, the fifth generation mobile communication system is expected to be used in the fields of transportation, smart cities, agriculture, forestry, fisheries, medical care, as well as creating new businesses.

Since the first generation mobile communication system in the 1980s, when analog cellular phones began to become popular in the private sector, cellular phones and communication technologies supporting them have been evolving daily. After the move to digital for 2G, 3G was developed to deal with high-speed, high-quality multimedia information. The use of broadband networks has also spread to mobile communications, and with 4G, the current main communication environment, we can enjoy videos easily using a smartphone or a tablet.

Evolution of mobile communications systems*

The above diagram was created by Fujitsu Ltd. based on the following document:

What is needed next is 5G. This fifth-generation system is required to create an environment that provides ultra-high speed, high capacity, multiple simultaneous connection, and low latency/high reliability, allowing everyone to enjoy comfortable and secure connectivity whenever they want. To enter the IoT era where all sorts of things, including wearable items and home appliances, are connected to networks, countries around the world are actively working on R&D and PoC (proof-of-concept) to commercialize 5G technology by 2020.

Fujitsu is advancing 5G R&D activities for High Capacity Technologies with Ultra High-Density Multi-Band and Multi-Access Layered Cells under a contract with the Ministry of Internal Affairs and Communications. In May 2014, Fujitsu and NTT DOCOMO, Inc. (hereinafter “DOCOMO”) agreed to cooperate in 5G experimental trials and have been actively working on a series of such trials.

*: Excerpt from The 17th committee materials of the Information and Communications Council, Information and Communications Technology Subcommittee, Committee for Faster Mobile Phones, of the Ministry of Internal Affairs and Communications

Achieving High Capacity with Ultra High-Density Distributed Antenna Systems

Fujitsu has conducted an experimental field trial for 5G communications in cooperation with DOCOMO to investigate differences between base stations with different (centralized/distributed) antenna configurations.

This experimental trial was conducted for a distributed base station configuration (where four antennas, each of which contains four elements, are distributed among four base stations) and a centralized base station configuration (where one antenna with 16 elements is located at one base station) in the 4.5 GHz band (with 200 MHz bandwidth). A radio-wave measuring vehicle (equipped with eight-element antennas moving at 5 km/h), simulating an environment where eight users walking at the same time, measured the system capacity obtained from each base station within the experimental section.

Trial environment

As a result of the trial, base stations in a distributed antenna configuration provided a maximum of 5 Gbps system capacity, with an average of 3.8 Gbps, which are higher and more stable than the centralized configuration method. Coordinated transmission** among distributed base stations provides high system capacity by reducing the interference between the base station antennas. With this transmission method, even if there are objects that shield radio waves, such as trees, communications are less likely to be disrupted, and more stable communication quality can be secured.

Trial results: Terminals' reception characteristics

**: A transmission technique in which multiple base stations coordinate with each other in transmitting signals

For the Roll-out of 5G in 2020

Fujitsu will advance research on ultra high-density distributed antenna technology and carry out experimental field trials in various environments in collaboration with DOCOMO. Fujitsu is also aiming to increase the capacity by more than 1,000 times from the current level, achieve a data communication speed exceeding 10 Gbps, and respond to an increase in the number of devices resulting from the spread of M2M communications, including sensor networks.

Fujitsu will continue to contribute to developing 5G technology toward the practical implementation of 5G communications by 2020.

This experimental trial includes a part of results of "The research and development project for realization of the fifth-generation mobile communications system" commissioned by The Ministry of Internal Affairs and Communications, Japan.