Indoors-Outdoors — 5Gs Dirty Little Secret

Mike Murphy, CTO for North America, Nokia Corp has some interesting insights into 5G, which will have some impacts on rural broadband. Eighty (80%) percent of traffic originates indoors and twenty (20%) percent outdoors. However mmWave 5G does not penetrate walls, windows, and trees very well if at all. It is important to remember that 5G is more than a cell phone carrier, it is being marketed as a broadband service, with some mobile phone capacity.

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Murphy explains:

. . . there is another dirty secret in the closet. The rule of thumb for capacity, as embedded in the 3GPP channel models, is that 80% of traffic originates indoors and 20% outdoors. Compounding that, there is a seasonal aspect to traffic. During the cold winter months in the north, there is even less traffic outdoors (likewise, in the hot summer months in the south). With LTE, indoor traffic is primarily served by outdoor cell sites, booming signals through walls and windows. This begs the question: What happens when 5G needs to handle that indoor traffic?

In the US, the Federal Communications Commission (FCC) is planning to auction off Millimeter Wave (mmWave) (24GHz, 28GHz and 39GHz) spectrum over the next two years. But mmWave doesn’t like hard things such as walls, windows and trees. Penetration loss is significant. This means 5G mmWave, practically, will not really be able to service indoor demand from outdoors-in (unlike low band LTE). (For completeness, we should note that T-Mobile US Inc. ‘s 600MHz spectrum and Sprint Corp. (NYSE: S) Band 41 spectrum (2.5GHz) can help in this situation to a degree. However, the number of petabytes needed is very significant, and it is unlikely these solutions alone will suffice.)

So where does this leave us? There are only two options. The first is to use low- or mid-band spectrum outdoors, and blast millimeter wave indoors; the outside-in approach. But in the dense urban case, we are already using that spectrum! So, the only real alternative is new mid-band spectrum. For the moment, none is in sight in the US until about 2020+ when the 3.7-4.2GHz band — or parts of it — become available. The other is to deploy mmWave indoors. The problem with going indoors versus using the outdoors-in approach is that everyone wants to get inside. Imagine Verizon, AT&T, Sprint, T-Mobile and all the others showing up at your building and wanting to deploy 5G mmWave inside every room. Perhaps neutral hosting solutions may help.

Before we finish, let’s dismiss one counter argument. Some will say, “But WiFi will fix that.” WiFi, however, has its own growth problems, thank you very much. WiFi demand is also growing, at least at 30% or more, and it too has looming capacity issues, with no significant new spectrum becoming available either.

Cellular demand, meanwhile, is separate, independent and additive. So, there is no getting around it. 5G needs to go and bang on some front doors.

Full Article at Light Reading 5G

Will the 5G providers be banging on the doors in small towns and villages to install mmWave 5G in multiple building after populating the town with small cell towers ever 500 feet. Not likely, as the costs would soon exceed the potential revenue. The mmWave spectrum is not the right technology for rural broadband, whereas LEO satellites seem to have more potential.

The rollout plan for 5G is to serve the dense urban areas and then the suburbs and finally some larger small cities in rural locations. The timeline is about ten years; thus the LEO satellite broadband will be available long before 5G gets anywhere near rural communities in the Sierra and elsewhere. LEO bandwidth should be available by 2020. Go Starlink and OneWeb!

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