I am writing this while flying back from the 6th
Brooklyn 5G Summit, with emphasis on the ‘5G’ even though the conference
leaders wanted to talk about 6G.
If some of you have started rolling your eyes, I can fully
understand. At the opening cocktail party, before the conference started, I
said to someone “I am trying to avoid saying the phrase ‘6G’.” only to discover
that was what he was working on. Sorry.
At the kickoff, Nokia Bell Labs President, Marcus Weldon,
and NYU Wireless head, Ted Rappaport riffed off the concept that this was start
of the 6G cycle, although Marcus estimated that the gap between “G’s” is
normally 15 years. Ten is probably closer to the truth (especially in Latin
America) but I (at least) appreciated his effort to calm our nerves over
talking about 6G too soon.
The Brooklyn 5G Summit is, fundamentally, an academic
conference. While Nokia is the lead sponsor and a key organizer, and Ericsson
and Huawei participate, the summit is held on the NYU Tandon School of
Engineering campus and Rappaport is clearly the leader of conference and its
Thus, the point of view that the academic / theoretical
issues with 5G have been (largely) resolved. Researchers are turning their
attention to what comes next.
Should have tried to
do some more
One of the drivers of 6G talk is the recognition that there
were things in the original design of 5G that not only did not make it into
3GPP Release 15 but will not be in Release 17, expected sometime in the first
half of the next decade.
A panel discussion with the three major equipment vendors
and members of the academic community admitted that, with the timelines fixed
independently of the amount of work or the resources available, those setting
standards simply ran out of time. Remember that Release 15 was brought forward
so that the South Koreans would have something for last year’s Winter Olympics.
Release 16 is somewhere between three months and six months late (depending on
who you ask or how you measure the original commitment) so it is likely to leave
some stuff behind in the interests of time as well.
We do not yet have 1 ms latency, nor it appears will we have
it even in Release 17. I guess that was a ‘stretch target’ although it got lots
of airplay when we started talking 5G. Both Release 16 and 17 are planning
Network Slicing Advanced, Massive MIMO Advanced and Massive IoT Advanced,
meaning that the Release 15 versions of these are (by implication) basic and
not delivering the expectation.
However, to be fair to all concerned, one speaker admitted
that the ‘deficiencies’ in Release 15 were less a matter of work not getting
done as they were ‘victims’ of overly hyped expectations. 5G’s advocates promised
everything that this generation will ever be. We all just (naively) thought
that the stuff they were talking about would be in Release 15. That never
happened in the past and it was foolish to think it would happen this time.
something to say
That said, the speakers found it
difficult to be concrete about what the research program for 6G might include.
Remember the eMBB-URLLC-Massive
IoT triangle we used to explain 5G? Marcus Weldon introduced a new “triangle of
truth” positing that 6G would integrate Hardware, Software and “Wetware” or the
biological sphere. Sounded vaguely like the Borg to me.
Ted Rappaport and his
collaborator Gerhard Fettweis were sure that 6G would involve ‘Teraherz
Communications’, that is, the band from 300 to 1,000 GHz. The capacity of such
a system would be amazing obviously but either cell radii would be measured in
meters (centimeters?) or the power would be so high that you could to cook your
lunch by putting your phone next to it, so I think there are more that a few
research problems to be worked on.
One solution is Even More
Massive MIMO (EMMMIMOTM Mirador Communicaciones SAS) so maybe it is
time to revive the ‘porcupine phone’ idea I posited a few years ago.
All agreed that there was
a wide scope for further research and that 3GPP would continue to churn out new
releases every few years. Somewhere in this sequence some marketing person will
decide to label the release 6G (for AT&T 7GE) and we will be in a new
generation. Maybe Marcus was indeed thinking of the Borg: resistance is futile.
Despite the emphasis on
higher and higher frequency bands to achieve higher and higher bandwidth albeit
in smaller and smaller cells or higher and higher cell density, no one I spoke
to expected there to be a new air interface in 6G (there was not one in 5G
after all) or even a new frame structure (the new one for 5G was thought to
have all the flexibility needed).
Rather 6G (and 7G and 8G)
were likely to be architectural improvements of the end-to-end system with
innovations in edge computing, cloud etc.
Giving up I close my
As I said in the cocktail party, my best strategy is to
ignore 6G. If Marcus is right, it may not come for a decade or so, and I am so
old already that I may never confront the upgrade decision.
There was lots of content at the summit that was purely 5G
including the posters and demos. Release 16 may be well advanced but there is
still much work to complete Release 17. The marketeers may decide Release 18 is
6G but I doubt those working on it would agree.
NYU Wireless may decide that next year’s conference is the
first ‘Brooklyn 6G Summit’ but I will still attend (if invited). There will be a
lot to learn and, I expect, most of the content will be 5G-related.
6G may be coming to the fore, but there is still much work
to get to 5G.
Title Reference: “To Five or Six to Fore?” or in numerals “2 5 or 6
to 4?” or, getting rid of a space and the question mark, “25
or 6 to 4” Chicago’s enigmatic hit from 1969. It got to number 7 in the UK,
number 4 in the US and number
2 in Canada. It is another song that I clearly recall when and where I
heard it the first time: a hot July night at my aunt’s cottage on Lovesick Lake
north of Peterborough, Ontario. It might have been on the local radio station,
although that had a very weak signal and so more likely via WOWO, Fort Wayne,
Indiana bouncing off the ionosphere, a phenomenon known (apparently) as “skywave radiation”.
The lyrics, while not gibberish by any means, are hard to make coherent and the
official explanation – it is about writing a song in the early morning, at 25
or 26 minutes before 4am – is frankly unconvincing even if that is what the
songwriter himself says. For a long time, I thought the title was “25 or 6-2-4”
which made no sense whatsoever.
25 or 6 to 4 Songwriter Robert
Lamm © Spirit Music Group, BMG Rights Management
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