T-Mobile CTO Neville Ray told the FCC his 600 MHz band 5G would be 19% more efficient than LTE. That's the primary 5G band T-Mobile is using across the country. In the 2500 MHz Sprint band, the increase is 52%. (Chart at left and larger below.) It is possible these numbers will prove lower in actual test. Over 80% of the 5G being deployed around the world is low and mid-band. Generally, this is 4G hardware with NR software, with speeds closer to 4G than to 5G millimetre wave. Sprint & T-Mobile will be 90%+ low and midband, little faster than LTE.
Millimeter wave, which Verizon is deploying widely, is about three times faster than LTE in the real world. See Verizon 5G: "I'm getting speeds of 900+ Mbps downstream 200+ upstream." AT&T is deploying mmWave to hotspots in dense urban areas, but intends low and mid-band for most of the country.
Why are so many claiming 5G is five and ten times faster? Many don't realize that most "5G" since the 3GPP Great Renaming in Spring 2018 is now 4G hardware with 5G NR software, not particularly fast. Actually, the majority of 5G is mid-band, 60% to 80% slower than mmWave and not very much better than LTE. Others use out of date LTE capabilities; since 2017, "Gig LTE" is delivering speeds usually between 100 and 400 megabits. (It's more than a gig in the lab, hence the name.)
Some are comparing actual average speeds of LTE with "peak" or "lab" speeds of mmWave. Actual speeds are often only a third of "peak" speeds. Others are using the 20 gigabit speed in the ITU IMT standard without realizing it is based on using three or four times the largest actual spectrum allocation, 800 MHz for Verizon.
Some are presenting "politician's truths." The telco lobbyists with million dollar influence campaigns include former politicians who have dropped their standards. Many are just ignorant, and have missed the fact that nearly no network engineers agree with the lobbyist's claims.
Sylvana Apicella of Ericsson provides an estimate that NR will only add 10% to 20% in FDD bands, the frequencies below 2100 MHz that are primarily used today.
5G, as Telefonica CTO Enrique Blanco noted, is an evolutionary step.
From Neville Ray, an explanation of why 5G likely is 19% to 52% better than LTE. That's much less than the impact of MIMO and Carrier Aggregation, 4 G technologies raising capacity 6-12 times. Ray is one of the best CTOs in the business and the facts in his FCC work stand up.
5G has higher spectral efficiency than LTE, resulting in higher capacity per unit of spectrum (Hz) s
Key 5G spectral efficiency enhancements include:
Lean carrier: optimized control signaling overhead
Increased Occupied bandwidth: uses more of the allocated spectrum block for traffic handling
MIMO code book improvement: better use of discrete layers for parallel communication
Interference Coordination Features: to mitigate degrading radio interference