What Will 6G Be?
IEEE CTN
Written By:
Alan Gatherer, Editor-in-Chief
Published: 29 Jun 2018
https://www.comsoc.org/publications/ctn/what-will-6g-be
The Start of 6G: A Survey of Who Is Saying What
Despite the fact that some folks are saying 4G has lots of legs and 5G will only arrive gradually, no big deal, (for full disclosure, my own company Huawei has made such noises [1]), there are people looking forward to what 6G might hold and how to get there. So what trends are emerging?
Trend 1: More Bits, More Spectrum
Of course the first place people go is to claim that we will get to an order of magnitude more bit rate [2]. The challenge of achieving tens of Gb/s, at least in an aggregated sense to a small region, will depend on finding yet more spectrum (or does it? Will we ever have a new G without a request for more spectrum?). In his 2017 keynote at WCNC [3] Gerhard Fettweis of TU Dresden pointed towards several bands between100 and 300GHz that showed some promise.
CTN Jun 2018 Figure 1
Figure from “FasterThanFiber: The Future of Multi-Gb/s Wireless”, IEEE Microwave Magazine, May 2009.
His department has done some testing at these frequencies and they are not alone in this. So maybe we will find the spectrum, but the challenges to achieve true mobility will be even greater than those currently facing mmW for 5G.
Trend 2: Increased Emphasis on Spatial Bandwidth
Several authors have pointed towards an increased integration of satellite communications to enhance bandwidth and also the spatial acuity of the 6G system [2]. Indeed it would seem that going forward it will become critical to measure success in terms of the ability to deliver bits per second per m3 rather than simply bits per second. Of course 5G is already all over the spatial multiplexing angle (if you will pardon the pun) of the problem with massive MIMO technology allowing directing of beams with high accuracy to individual users. But the industry has yet to properly come to grips with how to measure the true benefit of this technology, in our humble opinion, which of course is measured in dollars not dB, leaving many great technologies circling around waiting to be properly motivated for productization. Presumably 6G will arrive with this all sorted out and there will be a new push for technologies that enhance the spatial density of b/s as well as a new appreciation for its value. Indeed there are some efforts to enhance massive MIMO beyond the current state of the art with 6G as their target [11]. Anyway, we predict that there is much left to be done in spatial bandwidth enhancement beyond the current mMIMO offerings, which are, themselves, still struggling to really make an impact.
Part 1