5G millimeter waves can never go beyond dense urban areas, says T-Mobile

5G mobile networks have started to arrive, but only in very limited areas and among misleading statements by mobile operators.

While the four major US carriers have over-processed 5G to varying degrees, T-Mobile has now significantly acknowledged the major limitation of 5G. T-Mobile's technical director, Neville Ray, wrote in a blog post that the millimeter-wave spectrum used for 5G "will never be significantly reduced beyond small pockets of 5G hot spots in dense urban environments ". This would seem to preclude the possibility that the fastest speeds of 5G reach rural areas or perhaps even the suburbs.

Ray explained this GIF by showing that the millimeter frequencies are immediately blocked by a gate that closes halfway while the lowest 600 MHz signal is not affected:

High frequency, small coverage area

With 4G, operators have favored the "seafront spectrum" below 1 GHz to cover the entire United States, both rural and urban.

5G networks will use both low and high frequencies, but they are supposed to offer their highest speeds on millimeter waves. The spectrum of millimeter waves is generally defined to include frequencies between 30 GHz and 300 GHz. But in the context of 5G, operators and regulators typically have target frequencies between 24 and 90 GHz. The high frequency spectrum of T-Mobile includes licenses in the 28GHz and 39GHz frequency bands.

Millimeter waves are generally not used in cellular networks because they do not go far and are easily blocked by walls and other obstacles. This brings us to the extent to which high-speed 5G deployments will be expanded outside major cities, and T-Mobile's chief technology officer has explicitly stated that 5G millimeter-wave deployments would only be "small" pockets "of densely populated areas.

Ray wrote on his blog mainly to complain about AT & T and Verizon who claimed to be the first operators to offer 5G. His statement on high frequency limitations explained in part why T-Mobile had not yet launched 5G. (There is also the small problem of the lack of 5G phones on the market, aside from a Motorola phone sold by Verizon, which requires a hardware connection to access the 5G.)

"The 5G plan for Verizon mmWave users is for only a few, and it will never reach rural America," Ray wrote. Ray pointed out that early readers of Verizon's small 5G launch were struggling to find a signal.

"This is partly a matter of physics: the millimeter wave spectrum (mmWave) offers considerable potential in terms of speed and capacity, but it does not move far from the cell site and does not penetrate the materials at all. ", continued Ray. "It will never really scale beyond small pockets of 5G hot spots in dense urban environments."

The industry standard 5G has been designed to make higher frequencies in cellular networks viable with improved beamforming technology and mbadive MIMO technology. The 5G industry standard applies to all frequencies, from frequencies below 1 GHz to millimeter waves, to the spectrum "[a]A speed higher than 6 GHz is necessary to reach the very high speed speeds envisaged for the 5G. Currently, the 26GHz and / or 28GHz frequency bands have the most international support in this range, "said the GSMA mobile industry group in a white paper in November 2018.

The GSMA has qualified the use of spectrum above 24 GHz as "vital" for 5G at high speed. This is largely due to the huge amount of unused spectrum in the higher bands – it is much more difficult to find large unused spectrum blocks of less than 1 GHz.

"A very small footprint"

T-Mobile intends to use the spectrum of millimeter waves to provide "a huge capacity on a very small surface area," Ray wrote today. "It promises a lot of speed and capacity in the dense urban areas and gathering places of a lot of people." But it will still need spectrum of low and medium bands to cover larger areas with 5G, he wrote.

Ray criticized Verizon for "rolling[ing] He also criticized AT & T for renaming the 4G to "5G E" and deploying 5G in some cities without selling any 5G phones.

"I have exactly the same network equipment and the same network software as those of AT & T and Verizon, and it is impossible to launch it for the clients at the present time," he said. written.

The 5G standard calls for download speeds of 20 Gbps and a latency of 1 ms. A Verizon 5G speed test in Chicago revealed download speeds of 762 Mbps and latency of 19 ms. Verizon's 5G coverage in Chicago and Minneapolis, its two launching cities, is hard to find.

T-Mobile on-hypes 5G, too

Despite Ray's realism about the limits of millimeter wave signals, T-Mobile has not hesitated to exaggerate the benefits of 5G. CEO John Legere started a recent article on his blog complaining that "there are so many things noise and the misinformation on the 5G on the market that it's virtually impossible to separate the truth from BS. "

But in the next paragraph, Legere argued that 5G "is the most transformative technology in our lives" without providing any evidence to support this claim.

T-Mobile also claimed that it could only build a strong national 5G network if the government allowed it to buy Sprint, even though its own previous statements about its 5G plans contradicted these claims.

Ray's blog has once again formulated this fusion statement, even though recent reports suggest that US regulators are not convinced. Ray argued that T-Mobile and Sprint together would constitute "a truly national wide and deep 5G network" using a mix of low, medium and high band spectrum.

While Verizon is asking for $ 10 more per month for the 5G, Ray has promised that T-Mobile "will not charge our customers more for 5G, while Verizon and AT & T will continue to drive up prices."