Joe Madden, Founder, Mobile Experts
Mansoor Hanif, Director of Converged Networks, Research and Innovation, BT
Jos Beriere, HetNet Project Manager, KPN
Dr Tommy Svensson, Professor, Electrical Engineering, Chalmers University of Technology
Roberto Rodriguez Dorrego, Head of Spectrum Strategy, Telefόnica
In 5G deployment, the radio techniques at 3-4 GHz will be an extension of the Massive MIMO systems deployed today in TD-LTE at 2.5 GHz. However, in some areas millimeter-wave spectrum will be used for 5G, and we expect radio issues to be very different. Here are some of the inputs that we discussed in the mm-wave workshop at RAN World 2017:
- Trials have been conducted by EE/Phazr using a balloon with a small cell, to test mm-wave links. The Phazr CPE was mounted on the balloon and the balloon was lifted to a height of 15 meters. This test achieved 1.75 Gbps avg, with heavy wind, using 160 MHz bandwidth. Note that the downlink was using a mm-wave band, but the uplink was at at 5 GHz.
- KPN sees the mm-wave technology as an extension of fixed wires for broadband service, but without the slow time-to-market associated with wires. It’s not perfect but in many cases mm-wave FWA could be better than fiber for the business case. This is not universal, so KPN is likely to look at this technology in pockets, not as a nationwide deployment.
- Cameras are one interesting use case where fixed wireless access with high bandwidth will be needed.
- The mmMAGIC project studies the development of radio access technologies (RAT) in the 6 to 100 GHz range. mmMAGIC has worked together with METIS II to organize workshops and development collaboration in study of radio techniques. Together these groups are looking at hybrid backhaul and access networks. One objective is to develop radios with a very small form factor, to fit into handsets or other very small devices.
- SDMA (Spatial division multiple access) is a reasonable approach in mm-wave bands due to the high resolution that is possible at high frequencies. The mmMAGIC group is recommending the use of SDMA as a way to increase spectral efficiency.
- Stand-alone mm-wave 5G systems will require high density and a LOT of coordination between sites. There are some promising results in testing with very low order MIMO but for high capacity this has not been tested.