LTE and 5G are so close to Shannon limits you can't get a major performance gain from a traditional connection without breaking the laws of physics. There's only so much you can load on a single signal. The big advances in the last five years have come from using multiple antennas and multiple signals. (MIMO.)
Ronny Haraldsvik claims Cohere's "Spectrum Multiplier software can effectively double network capacity and the capabilities of existing spectrum, supporting twice as many users and devices." That sounds like the kind of bs claim I'd normally ignore. But Cohere has convinced top engineers at major telcos they may have something.
Similarly, Tarana Wireless may have some exciting technology. Neil McRae of BT says
“After just one day of running our pilot on G1, customers are saying ‘please, you’re not going to turn this off for years, right!?!’ It’s a very sticky product.”
MTN in South Africa is in production with Tarana.
Both companies are loaded with respected industry executives and have done successful fundraising. I haven't been able to look closely at the tech so can't endorse anything, But enough people I respect are impressed I wanted to do a quick write-up.
Wireless can get much better, experts tell me
Some top researchers are convinced that sending multiple signals, perhaps from separate locations, has enormous potential. Andrea Goldsmith in 2014 said extending Shannon's Law to multiple signals was the most important problem on wireless theory. Almost a Hilbert problem for our field. (Andrea has left Stanford and now is Dean at Princeton.)
Peiying Zhu of Huawei taught me about "cell free" and Tom Marzetta "distributed massive MIMO," related ideas There's enormous potential in central control of what is sent from multiple sites. Huawei is doing some field trials. DMM probably is the next major advance in network performance, in some circumstances doubling bandwidth. It may be deliverable in a few years, far sooner than "6G."
I don't know if Tarana or Cohere has delivered on those hopes, but it's not impossible.